Sjabloon:Harvard citation documentation

The Harv family of templates are used for creating short-cites (or "short citations"), typically used as in-line citations, that link to the full citation (with the full bibliographic details) for a source. This enables a source to be cited multiple times, with each short-cite having an in-source specification (such as a page number) and any other details or comments pertinent to that specific instance. This functionality eliminates the need for replicating notes with "named-refs" (the "<ref> name= ...>" construct).

The sfn – "shortened footnote" — templates create notes (footnotes) containing harv templates.

Note that the use (or even non-use) of these templates is an element of citation "style", and adding or removing them in articles with an established style should be consistent with that style. See WP:CITEVAR.

Placing the template in the body of the article

{{{{{1}}} | last name(s) of author(s) | year | p=page number or pp=page range or loc=other location}}

Last names of editors can be used, if no authors are given, as author names are given precedence.

If more than four authors, truncate the list to the first four.

In the references section (or in an earlier footnote):

{{cite book or cite journal, etc | ref=harv | ... other appropriate parameters ... }}

or

{{citation | ... other appropriate parameters ... }} (|ref=harv is not required when using {{Citation}}).

Parameters

Up to four authors can be given as parameters. (If there are more than 4 authors only the first 4 should be listed. See § Large numbers of authors, below.) The last required parameter is the year of publication.

(All these examples have links which operate. Click on highlighted text.)

Markup	Renders as
{{{{{1}}}|Smith|2005|p=25}}	{{{{{1}}}|Smith|2005|p=25}}
{{{{{1}}}|Smith|Jones|2005|p=25}}	{{{{{1}}}|Smith|Jones|2005|p=25}}
{{{{{1}}}|Smith|Jones|Brown|2005|p=25}}	{{{{{1}}}|Smith|Jones|Brown|2005|p=25}}
{{{{{1}}}|Smith|Jones|Brown|Black|2005|p=25}}	{{{{{1}}}|Smith|Jones|Brown|Black|2005|p=25}}

The optional parameters |p=, |pp= and |loc= can be used to indicate the location in the source. All of the Harvard citation templates use the same parameters to indicate page numbers or other locations in the text. For single pages, use |p=; and for multiple pages (such as ranges), use |pp=. Use of |p= for multiple pages or |pp= for single pages can cause cite errors.

Markup	Renders as
{{{{{1}}}|Smith|2005|p=25}}	{{{{{1}}}|Smith|2005|p=25}}
{{{{{1}}}|Smith|2005|pp=25–26}}	{{{{{1}}}|Smith|2005|pp=25–26}}
{{{{{1}}}|Smith|2005|loc=chpt. 3}}	{{{{{1}}}|Smith|2005|loc=chpt. 3}}
{{{{{1}}}|Smith|2005|loc=section 7}}	{{{{{1}}}|Smith|2005|loc=section 7}}

The optional parameter |ref= is used to specify the reference value that links the short citation to the full citation. This parameter is usually not necessary and it is more common to use {{sfnRef}} or {{harvid}} in the reference section. If you specify |ref=none no hyperlink is created. Note that, if one does not want the link, it is always possible to simply not use the template. (Not available in {{sfn}} and similar templates.)

Aliases

The parameters |page= |pages= and |Ref= exist as aliases for |p= |pp= and |ref= respectively.

Author–date citation templates

There are several templates used to create in-text citations; they differ in the use and placement of parenthesis, in the separator before the page or location and in whether a terminal full stop (period) is present:

In-text templates

Templates	Aliases	Example
{{Harvard citation no brackets}}	{{harvnb}}
{{Harvard citation}}	{{harv}}
{{Harvard citation text}}	{{harvtxt}}
{{Harvcoltxt}}
{{Harvcol}}
{{Harvcolnb}}
{{Harvard citations}}	({{harvs}})	John Smith (2006, 2007) (and many other forms).
{{Harvp}}
{{Shortened footnote template}}	{{sfn}}	Article text.
{{Sfnp}}		Article text.
{{Sfnm}}		Article text.
{{Sfnmp}}		Article text.

Full citations can be created manually or by templates:

• Citation Style 1 templates
• {{citation}}

All of these templates have the same parameters and basic functionality. This page describes all of them except the parameters of {{sfnm}} and {{harvs}}; please see their documentation pages. Editors editing one of these templates are requested to make parallel changes to the other versions.

Applications in the body of the article

Harvard citation: {{harv}}

Template {{harv}} creates a parenthetical reference with a link to the full citation in the references section at the bottom of the article.

Markup	Renders as
Article text {{harv|Smith|2006|p=25}}. ==References== * {{cite book | ref = harv | last = Smith | first = John | title = Smith's book | year = 2006 }}	Article text . References Smith, John (2006). Smith's book.

Shortened footnote: {{sfn}} or {{harvnb}}

Template {{harvnb}} inside a <ref> span can be used to create a Shortened footnotes that is linked to the full citation at the bottom of the article. Template {{sfn}} (without the use of <ref>) has the same effect and it also combines identical footnotes automatically.

Markup	Renders as
Article text.{{sfn|Smith|2007|p=25}} More article text.{{sfn|Smith|2007|p=25}} Still more article text.{{sfn|Smith|2007|p=26}} ==Notes== {{reflist}} ==References== * {{cite book | ref = harv | last = Smith | first = John | year = 2007 | title = Smith's Book }}	Article text. More article text. Still more article text. Notes References Smith, John (2007). Smith's Book.
Article text.<ref name=Smith2008p25>{{harvnb|Smith|2008|p=25}}.</ref> More article text.<ref name=Smith2008p25/> Still more article text.<ref>{{harvnb|Smith|2008|p=26}}.</ref> ==Notes== {{reflist}} ==References== * {{cite book | ref = harv | last = Smith | first = John | year = 2008 | title = Smith's Book }}	Article text. More article text. Still more article text. Notes References Smith, John (2008). Smith's Book.

In text attribution: {{harvtxt}}

Template {{harvtxt}} can be used to link an in-text attribution to the full citation at the bottom of the page.

Markup	Renders as
According to {{harvtxt|Smith|2009|p=25}} ... ==References== * {{citation | last = Smith | first = John | year = 2009 | title = Smith's Book }}	According to ... References Smith, John (2009), Smith's Book

Bundled citation: {{harvnb}} or {{sfnm}}

Template {{harvnb}} can be used to bundle citations. {{sfnm}} also produces bundled citations.

Markup	Renders as
Article text ({{harvnb|Smith|2010|p=25}}; {{harvnb|Jones|2010}}).	Article text (; ).
Article text.<ref>{{harvnb|Smith|2010|p=25}}; {{harvnb|Jones|2010}}</ref>	Article text. Notes
Article text.{{sfnm|la1=Smith|y1=2010|p1=25|la2=Jones|y2=2010}}	Article text. Notes
==References== * {{cite book | last = Smith | first = John ... Smith's book }} * {{cite book | last = Jones | first = Mary ... Jones' book }}	References Smith, John (2010). Smith's book. Jones, Mary (2010). Jones' book.

Note that {{sfn}} is inappropriate for bundled citations; use {{harvnb}} or {{sfnm}}.

More exotic Harvard citations {{harvid}} or {{harvs}}

More exotic Harvard citations can be constructed using the {{harvs}} template, such as multiple papers by the same author, using both the first and last names, links to articles about the author, and others. Any kind of unusual link can also be constructed using the idiom [[#{{harvid|parameters}}|link name]].

Markup	Renders as
The theory was developed by {{harvs|txt|first=F. J.|last=Murray|author1-link=F. J. Murray|first2=J.|last2=von Neumann|author2-link=John von Neumann|year=1936|year2=1937|year3=1943}}.	The theory was developed by F. J. Murray and J. von Neumann (1936, 1937, 1943).
The theory was developed by [[F. J. Murray]] and [[John von Neumann|J. von Neumann]] ([[#{{harvid|Murray|von Neumann|1936}}|1936]],[[#{{harvid|Murray|von Neumann|1937}}|1937]],[[#{{harvid|Murray|von Neumann|1943}}|1943]]).	The theory was developed by F. J. Murray and J. von Neumann (1936, 1937, 1943).
== References == * {{citation | last1 = Murray | first1 = F. J. | year = 1936 | ...}} * {{citation | last1 = Murray | first1 = F. J. | year = 1937 | ...}} * {{citation | last1 = Murray | first1 = F. J. | year = 1943 | ...}}	References Murray, F. J.; von Neumann, John (1936), Mathematics Paper Murray, F. J.; von Neumann, John (1937), Another Mathematics Paper Murray, F. J.; von Neumann, John (1943), Yet Another Mathematics Paper

Some articles use this idiom [[#CITEREFid | link name ]]. See notes on implementation details below.

Variations

Using colon format: {{harvcol}}, {{harvcolnb}}, {{harvcoltxt}}

Templates {{harvcol}}, {{harvcolnb}}, {{harvcoltxt}} use a colon to indicate the page number(s) or location.

Markup	Renders as
{{harvcol|Smith|2011|p=25}}
{{harvcolnb|Smith|2011|p=25}}
{{harvcoltxt|Smith|2011|p=25}}
{{harvcol|Smith|2011|p=25–26}}
{{harvcol|Smith|2011|loc=chpt. 3}}

Parenthesis around the year: {{sfnp}} and {{harvp}}

Template {{sfnp}} puts parenthesis around the year. Compare the two examples.

Markup	Renders as
Article text.{{sfnp|Smith|2011}} == Notes == {{reflist}}	Article text. Notes
Article text.{{sfn|Smith|2011}} == Notes == {{reflist}}	Article text. Notes

Similarly, in order to mimic Citation Style 1 citations, template {{harvp}} puts parenthesis around the year.

Markup	Renders as
{{harvp|Smith|2011|p=25}}

Additional comments or quotes: |ps=

Parameter |ps= can be used to add quotes or additional comments. Note that this effect can also be achieved using {{harvnb}}, if done as shown in the last example. The postscript is only effective the first time {{sfn}} is used for a particular author, year and location.

Markup	Renders as
Some information.{{sfn|Smith|2011|p=2|ps=: "A quote verifying the information."}} == Notes == {{reflist}}	Some information. Notes
"A quote in a secondary source."{{sfn|Smith|2011|p=2|ps=, quoted in {{harvtxt|Jones|2010|p=343}}}} == Notes == {{reflist}}	"A quote in a secondary source." Notes
Some information.<ref>{{harvnb|Smith|2011|p=2}}: "A quote verifying the information."</ref> == Notes == {{reflist}}	Some information. Notes

: two or more {{sfn}} templates with same authors, same year, same page, but different |ps= will result in a message. This message happens because the reference names that {{sfn}} creates will be the same but the content between the <ref name="FOOTNOTE..."> tag and the </ref> tag will be different. A work-around is to convert one or some of the {{sfn}} templates to {{harvnb}} wrapped in <ref>...</ref> tags.

No closing period: |ps=none

Using |ps=none in {{sfn}} removes the final period. Compare the two examples. Suppressing the default period (full stop) ensures consistency with Citation style 2, as produced by {{Citation}}, which does not use a trailing period (full stop) in notes. The postscript is only effective the first time {{sfn}} is used for a particular author, year and location. |ps= will also suppress terminal punctuation. Follow-on editors who encounter 'empty' parameters can't know if a previous editor intended to leave that parameter blank. Using the keyword none is a positive indication of the previous editor's intent.

Markup	Renders as
Article text.{{sfn|Smith|2011|ps=none}} == Notes == {{reflist}}	Article text. Notes
Article text.{{sfn|Smith|2011}} == Notes == {{reflist}}	Article text. Notes

Adding a URL for the page or location

If a specific link to the page or section is available, a URL can be added to the location or page number.

Markup	Renders as
{{harv|Smith|2011|loc=[http://en.wikipedia.org chpt 3]}}
{{harv|Smith|2011|loc=[http://en.wikipedia.org §7]}}
Article text.{{sfn|Smith|2011|p=[http://en.wikipedia.org 3]}} ==Notes== {{reflist}} ==References== * {{cite book | last = Smith | year = 2011 | title = Smith's other book }}	Article text. Notes References Smith (2011). Smith's other book.

Corresponding edits to the Reference section required

The Harvard citation templates used in the body of the article contain links. These links can find anchors in the references section, provided the anchors are included within Citation Style 1, Citation Style 2 or similar templates. To make the anchor, parameter |ref=harv must be set. This is not necessary for {{citation}}, but is normally necessary for the others.

Markup	Renders as
==References== * {{citation | title = Smith's paper |... }} * {{cite web | title = Smith & Jones website | ... | ref = harv }} * {{cite news | title = Article by Smith, Jones and Brown | ... | ref = harv }} * {{cite journal | title= Smith, Jones, Brown and Black's Paper | ... | ref = harv }}	References Smith, John (2005), Smith's paper Smith, John; Jones, Sam (2005). "Smith & Jones website". Smith, John; Jones, Sam; Brown, Tom (2005). "Article by Smith, Jones and Brown". Big Urban Newspaper. Smith; Jones; Brown; Black (2005). "Smith, Jones, Brown and Black's Paper". Important Journal.

Possible issues

Wikilink to citation does not work

If an article is using this template, and nothing happens when you click on the highlighted wikilink from a Harvard style citation to a full citation at the bottom of the page, there are several possible solutions. If:

1. The correct citation does not appear at the bottom of the article. Solution: Find the source (it may be copied from an article on a similar subject), and check that it verifies the text. If the source can't be found, tag the citation with {{citation not found}}.
2. The correct citation appears at the bottom of the article, and
   1. The Harvard citation uses a template (such as {{sfn}} or {{harv}}):
      1. The citation uses a template from the list at Citation Style 1:
         1. The name is spelled or capitalized differently here than the citation. Solution: check the source for the correct spelling.
         2. The year is different here than the citation. Solution: check the source for the correct year.
         3. The citation template requires |ref=harv (not needed for {{citation}}, but is needed for most other Citation Style 1 templates). Solution: Add |ref=harv.
         4. The template has a |date= field and no |year= field, but the format of the |date= field is unusual. Solution: Try to fix the date. If the link still does not work, add |year= to the citation template. (It's okay if it has both.)
         5. The citation does not have an author's, or an editor's, last name (authors take precedence over editors). Solution: check that |ref={{harvid}} is set correctly (see below).
      2. The citation uses a Citation Style Vancouver template. Solution: check that |harvid= is set correctly (see below).
      3. The citation uses a template that does not support |ref= (See Wikipedia:Citation templates and reference anchors). Solution: An anchor can be created using {{wikicite|id={{harvid|args}}|reference={{citation}}}}.
      4. The citation does not use a template:
         1. It has no wikicode to create an anchor. Solution: If {{cite *}} citation templates are used liberally throughout the article, then reformat the citation with the appropriate {{cite *}} template and set the |ref= appropriately. Otherwise consult with local editors on the talk page about how to proceed. Either add {{cite *}} templates and {{harv}} templates, or remove all templates, depending on what local editors prefer. A few articles use {{wikicite}} to create an anchor as an alternative to standard templates.
         2. Uses a <cite>...</cite> span to create an anchor. Solution: remove the cite span (these are deprecated) and proceed as with the previous.
         3. Uses {{wikicite}}. Solution: Check that |id={{harvid}} matches.
   2. If the Harvard citation uses a handwritten wikilink, such as [[#Reference-Smith2006|Smith (2006)]]
      1. The citation uses a citation template which supports |ref= (See Wikipedia:Citation templates and reference anchors). Solution: Check that |ref= is set to a matching id.
      2. Otherwise, check that the reference has {{wikicite|ref=id|reference=citation}} with a matching id.

Templates that have broken wikilinks using these templates are added to the category Category:All articles with broken links to citations.

More than one work in a year

Where there is a need to cite more than one work by the same author published in the same year, the standard way to disambiguate such works is to add a letter suffix after the year element of the {{sfn}} template (e.g. {{sfn|Smith|2006a}} and {{sfn|Smith|2006b}}).

Templates that use Module:Citation/CS1

When {{sfn}} is used with {{citation}} or Citation Style 1 templates, a year-suffix letter may be added to |date= for all accepted date formats except year initial numeric (YYYY-MM-DD). It is not necessary to include both |year= and |date=. If both are included, |year= is used for the CITEREF anchor to be compliant with legacy citations.

|date=2013a – simple year only dates

|date=Jan 2013b or |date=Winter 2013b – month or season and year dates

|date=9 November 2013b or |date=November 9, 2013b – full dates

|date=June–July 2013c or |date=Winter–Spring 2013c – month or season ranges and year dates

|date=c. 2013d – circa year dates

|date=2024–2025f or |date=Summer 2024–25f – year ranges

|date=n.d.e – no date (n.d.)

|date=2013x-11-09 – not supported, the template must use |year=2013x

Markup	Renders as
Article text.{{sfn|Smith|1993a|p=25}} More text.{{sfn|Smith|1993b|p=32}} ==Notes== {{reflist |close=1}} ==References== * {{cite journal |last=Smith |first=Karen |date=January 1993a |title=Smith's first paper |journal=Important Journal |ref=harv }} * {{cite journal |last=Smith |first=Karen |date=Spring–Summer 1993b |title=Smith's second paper |journal=Another Important Journal |ref =harv }}	Article text. More text. Notes References Smith, Karen (January 1993a). "Smith's first paper". Important Journal. Smith, Karen (Spring–Summer 1993b). "Smith's second paper". Another Important Journal.

More than one author with the same last name

The above solution to add a letter suffix after the year element also works for multiple authors with the same last name. For example, both Richard Bushman and Claudia Lauper Bushman published books in 2006. To differentiate between the two books, the first one is given the year "2006a" and the second one "2006b".

Large numbers of authors

Only the first four authors are required by the template. Listing more is not supported. It is also possible to use the |ref={{harvid}} in the citation template, which allows a more concise citation in the article text.

Markup	Renders as
Article text {{harv|Smith|Jones|Brown|Black|1994|p=25}}. ==References== * {{cite journal | last = Smith | last2 = Jones | last3 = Brown | last4 = Black | last5 = Davis | last6 = Martinez | last7 = Hsu | year= 1994 | title= Scientific paper written by dozens of scientists | journal = Important Journal | ref = harv }}	Article text . References Smith; Jones; Brown; Black; Davis; Martinez; Hsu (1994). "Scientific paper written by dozens of scientists". Important Journal.
Article text {{harv|Smith et al.|1995|p=25}}. ==References== * {{cite journal | last = Smith | last2 = Jones | last3 = Brown | last4 = Black | last5 = Davis | last6 = Martinez | last7 = Hsu | year= 1995 | title= Another paper by even more scientists | journal = Important Journal | ref = {{harvid|Smith et al.|1995}} }}	Article text . References Smith; Jones; Brown; Black; Davis; Martinez; Hsu (1995). "Another paper by even more scientists". Important Journal.

No author name in citation template

Some sources do not have a single author with a last name, such as a magazine article or a report from a government institution. There is no consensus (in Wikipedia or among citation styles) about how to format author–date citations to works that do not have a specific author. Several choices are:

1. For a newspaper or periodical you may use the name of the paper and the date.
2. For a publication by an institution, use either:
   1. The initials of the institution
   2. The name of the institution
3. Alternatively, some style guides recommend using the title of the article.
4. Other style guides recommend using "Anonymous" or "Anon."

An article should adopt one of these styles consistently. Using |ref={{harvid}} in the citation template can handle these cases.

Markup	Renders as
Article text.{{sfn |BGI|1996|p=429}} ==Notes== {{reflist}} ==References== * {{cite book | title = Important Book | year = 1996 | publisher = Big Government Institution | ref = {{harvid|BGI|1996}} }}	Article text. Notes References Important Book. Big Government Institution. 1996.
Article text.{{sfn |''Popular Magazine''|1996|p=29}} ==Notes== {{reflist}} ==References== * {{cite magazine | magazine = Popular Magazine | title = An Article by an Anonymous Author | year = 1996 | ref = {{harvid|Popular Magazine|1996}} }}	Article text. Notes References "An Article by an Anonymous Author". Popular Magazine. 1996.

Citation has |date= and no |year=

Either the |year= or |date= of a citation template can be matched – the template logic can extract the year from a full date. If the date parameter is not a full date, then the extraction will fail. If the link does not seem to work, it also possible to set both |date= and |year= parameters. The template will display the date and use the year for the anchor. If only the year is known the |year= field must be used in the citation for the link to work correctly (i.e. |date=2005 may not work correctly). These two examples show a year being successfully extracted from full date.

Markup	Renders as
Article text.{{sfn|Smith|1997|p=101}} ==Notes== {{reflist}} ==References== * {{cite journal | last = Smith | first = Karen | date = 11 May 1997 | title = Smith's 1997 paper | journal= Important Journal | ref = harv }}	Article text. Notes References Smith, Karen (11 May 1997). "Smith's 1997 paper". Important Journal.
Article text.{{sfn|Smith|1998|p=101}} ==Notes== {{reflist}} ==References== * {{cite journal | last = Smith | first = Karen | date = May 1998 | title = Smith's 1998 paper | journal= Important Journal | ref = harv }}	Article text. Notes References Smith, Karen (May 1998). "Smith's 1998 paper". Important Journal.

Citation template does not support |ref=harv

The Citation Style Vancouver family of templates use parameter |ref=harvid to create an anchor for the Harvard citation templates. This must be set to a concatenation of the parameters passed to the Harvard citation template.

Markup	Renders as
Article text.{{sfn|Smith|1999|p=101}} ==Notes== {{reflist}} ==References== * {{vcite book | author = Smith K | year = 1999 | title = Smith's 1999 Book | harvid = Smith1999 }}	Article text. Notes References Smith K. Smith's 1999 Book. 1999.
Article text.{{sfn|Smith|2000|p=101}} ==Notes== {{reflist}} ==References== * {{cite thesis | last = Smith | first = Karen | date = May 2000 | title = Smith's Thesis | ref = {{harvid|Smith|2000}} }}	Article text. Notes References Smith, Karen (May 2000). Smith's Thesis (Thesis).

Citation format does not support anchors: {{wikicite}}

In a few very rare cases, it may be impossible for the citation templates to create an anchor. Either (1) the citation is formatted with a template that does not support the |ref= parameter or (2) the source can't be described using our citation templates at all. In these cases, it is possible to use {{wikicite}} to make the anchor. (As of November 2010, there are only approximately 100 articles that require this technique.) It is also possible that (3) local editors would prefer not to use citation templates. In this case, it is important to discuss what the local editors would like to do about the bad links. It is always possible to simply remove {{harv}} or {{sfn}}.

Markup	Renders as
Article text.{{sfn |Big Government Agency|1999}} ==Notes== {{reflist}} ==References== * {{wikicite | reference = {{cite report | title=Important Government Report | publisher=Big Government Agency | year=1999 }} | ref = {{harvid|Big Government Agency|1999}} }}	Article text. Notes References Important Government Report (Report). Big Government Agency. 1999.
Article text.{{sfn |A particularly unusual citation}} ==Notes== {{reflist}} ==References== * {{wikicite | reference = A source that can't be described using our citation templates at all. | ref = {{harvid|A particularly unusual citation}} }}	Article text. Notes References A source that can't be described using our citation templates at all.

It is also possible to use <cite> to achieve the same effect, but this may not be compatible with HTML 5.

Citation has multiple authors and no date

The templates assume that the last field is the year. Where there are multiple authors and no year the template will form a correct link but will display the last author as if it were a year. To force the displayed text to show all authors as name, the following work around may be used:

Markup	Renders as
Article text.<ref>[[#{{harvid|Lane|Singh}}|Lane & Singh]]</ref> ==Notes== {{reflist}} ==References== * {{citation | last = Lane | first = Kieran | last2 = Singh | first2 = Karun | title = Richard Watts | work = Richard Watts Charities | url = http://www.richardwatts.org.uk/richardwatts1.html | accessdate = 21 June 2012 }}	Article text. Notes References Lane, Kieran; Singh, Karun, "Richard Watts", Richard Watts Charities, retrieved 21 June 2012

Recommended style

The recommended Harvard referencing style potentially uses all four templates. Each automatically generates a hypertext link based on the name(s) and date. Here is an example

Markup	Renders as
Some works on gravitation are so massive they warp spacetime themselves {{Harv|Misner|Thorne|Wheeler|1973}}; yet {{Harvtxt|Einstein|1915}} presented essential equations with notable brevity. The essential ingredients are the curvature tensor and the stress–energy tensor ({{Harvnb|Einstein|1915|p=844}}; {{Harvnb|Misner|Thorne|Wheeler|1973|p=41}}). ==References== *{{Citation | last=Misner | first=Charles W. | last2=Thorne | first2=Kip S. | first3=John Archibald | last3=Wheeler | title=Gravitation | publisher=W. H. Freeman | location = San Francisco | date = September 1973 | isbn = 0-7167-0344-0 }} *{{Citation | last =Einstein | first =Albert | title =Die Feldgleichungen der Gravitation (The Field Equations of Gravitation) | journal =Königlich Preussische Akademie der Wissenschaften | pages =844–847 | year =1915 }}	Some works on gravitation are so massive they warp spacetime themselves ; yet presented essential equations with notable brevity. The two ingredients are the curvature tensor and the stress–energy tensor (; ). References Misner, Charles W.; Thorne, Kip S.; Wheeler, John Archibald (September 1973), Gravitation, San Francisco: W. H. Freeman, ISBN 0-7167-0344-0 Einstein, Albert (1915), "Die Feldgleichungen der Gravitation (The Field Equations of Gravitation)", Königlich Preussische Akademie der Wissenschaften: 844–847

In short:

1. For a single work with no author in the text (the most common case), use {{Harv}}.
2. For a single work with the author named in the text, use {{Harvtxt}}.
3. For multiple works at the same point, use explicit parentheses and {{Harvnb}} separated by semicolons.
4. For anything more complicated use {{Harvs}}.

Implementation notes

These templates use two elements: a wikilink in the body of the article, and an anchor in the reference section of the article. Clicking on the wikilink repositions the page at the anchor.

Citation template anchor

The most common citation templates are Citation Style 1 or Citation Style 2. If |ref=harv is set, then Module:Citation/CS1 and {{Citation/core}} create an anchor <a name="CITEREF"> followed by the concatenation of the following parameters:

• last or last1 or surname or surname1 or author or author1 or authors,
• last2 or surname2 or author2,
• last3 or surname3 or author3,
• last4 or surname4 or author4,
• editor-last or editor-surname or editor1-last or editor1-surname or editor or editors,
• editor2-last or editor2-surname,
• editor3-last or editor3-surname,
• editor4-last or editor4-surname,
• year.

Template {{Citation}} sets |ref=harv as the default.

This covers the most common templates. Information about all the templates is available at Wikipedia:Citation templates and reference anchors.

Use of the date parameter in place of the year parameter in citation templates is preferred when full dates are known.

Harvard citation wikilink

The Harvard citation templates create a wikilink to the anchor. For example {{Harv|Smith|2006|p=25}} produces the link <syntaxhighlight lang="text" class="" id="" style="" inline="1">#CITEREFSmith2006</syntaxhighlight> and {{Citation|last=Smith|first=John|date=27 January 2006|title=My Life}} produces the anchor <syntaxhighlight lang="text" class="" id="" style="" inline="1">CITEREFSmith2006</syntaxhighlight>.

Using CITEREF directly

A few articles create a custom ID using <syntaxhighlight lang="text" class="" id="" style="" inline="1">CITEREF</syntaxhighlight>, either in place of the Harvard citation template (e.g. [[#CITEREFSmith2006|(2006)]]) or as a value for |ref= in the citation template. A custom ID must follow these rules:

• Names are case-sensitive. Please do not use raNdOM capitalization.
• Names must not be purely numeric; the software will accept something like ":1" (which is punctuation plus a number), but it will ignore "1" (purely numeric).
• Names should have semantic value, so that they can be more easily distinguished from each other by human editors who are looking at the wikitext. This means that ref names like "Nguyen 2010" are preferred to names like ":1".
• Names must be unique. You may not use the same name to define different groups or footnotes.
• Please consider keeping reference names simple and restricted to the standard English alphabet and numerals. Failing that, including if spaces are used, the following technical restrictions become relevant:
  • Quotation marks are preferred but optional if the only characters used are letters A–Z, a–z, digits 0–9, and the symbols !$%&()*,-.:;<@[]^_`{|}~. That is, all printable ASCII characters except #"'/=>?\.
  • Inclusion of any other characters, including spaces, requires that the reference name be enclosed in quotes; for example, name="John Smith".
  • The quote marks must be the standard, straight, double quotation marks ("); curly or other quotes will be parsed as part of the reference name.
  • Quote-enclosed reference names may not include a less-than sign (<) or a double straight quote symbol ("). These may be escaped with < and ", respectively.
• If CITEREF is used, then spaces in the |ref= field must be replaced with underscores
• You may optionally provide reference names even when the reference name is not required. This makes later re-use of the sourced reference easier.

Examples:

• {{sfn|cite name|year}}
• {{cite book|ref=CITEREFcite_nameyear}}
• {{cite book|ref={{sfnref}}}}

Where cite_name is a name such as the publisher.

{{sfn}}'s ref name

Template {{sfn}} creates a named footnote, so that identical footnotes are combined automatically. The footnote name begins with <syntaxhighlight lang="text" class="" id="" style="" inline="1">FOOTNOTE</syntaxhighlight> followed by a concatenation of the arguments to {{sfn}}. E.g.: this template call {{sfn|Smith|2006|p=26}} should have exactly the same functionality as <ref name="FOOTNOTESmith200626">{{Harvnb}}</ref> which, in turn, has the same functionality as <ref name="FOOTNOTESmith200626">[[#CITEREFSmith2006|Smith (2006)]], p. 26</ref>.

The ref name becomes more complicated when the page (p) parameter includes a URL, e.g. {{sfn|Joyce|1903|p=[https://archive.org/details/aconcisehistory00joycgoog/page/n226 213]}}, which, once defined, can be called by <ref name="FOOTNOTEJoyce1903[httpsarchiveorgdetailsaconcisehistory00joycgoogpagen226 213]" />. The "p=" and the characters |,:,.,/,?,=; are therefore stripped out of the URL.

The call to {{harvnb}} has been subst'ed for quicker load times.