This is an essay on methods of citing sources. It contains the advice or opinions of one or more Wikipedia contributors. This page is not an encyclopedia article, nor is it one of Wikipedia's policies or guidelines, as it has not been thoroughly vetted by the community. Some essays represent widespread norms; others only represent minority viewpoints.

This page in a nutshell: This article describes and compares various methods for citing sources and includes a recommendation for the author's preferred method.

Citing sources is fundamental to Wikipedia but understanding the process is complicated by (A) the use of multiple citation styles and (B) a wide variety of citation-related tools and templates. The Citing sources page is the official Wikipedia page on how to format and present citations, but it includes a lot of information about when to add citations and other topics that are unrelated to how to add them. This page gives a brief description of the most common citation methods and includes an assessment of the pros and cons of each method.

Terminology

"Article" vs. "article text"

When I refer to the "article", I mean the version of the article that readers see. When I refer to the "article text", I mean the text of the article that includes the wiki code that is visible when you edit the page.

Using plain text

In the method descriptions below, the qualifier using plain text indicates that the editor is responsible for specifying the citation details in the proper style, i.e., in the proper sequence, using the proper punctuation, and applying the appropriate character formatting. For more information about citation styles, see " How to format citations".

Using templates

In the method descriptions below, the qualifier using templates is an alternative to using plain text and indicates that the editor has chosen to use citation templates to create the citations. Using citation templates eliminates the need for editors to know citation style details and improves the consistency of the citations, but the editor does have to learn how to use a handful of similar templates including {{ cite book}}, {{ cite news}}, and {{ cite web}}.

Page source

The examples below include the text required to create citations using various methods. If you review the source of this page, you will see that the actual text in the examples often differs from the text shown. This was necessary due to the unusual nature of this page where there are multiple citation methods used, multiple Notes and References sections, etc. When editing an actual article, you can use the article text shown in the examples.

Methods

General references

A general reference is a source that is not tied to a specific assertion in the text.

To add a general reference:

1. Add a References section if the article does not have one already.
2. Add an entry to the list of references.

General references are rarely worth the effort to add them to the article; they do not explicitly support any particular assertion in the article and so they do not help readers verify that the material has already been published by a reliable source. When an article makes many assertions, it's not practical for the reader to verify which assertions in the article are supported by a general reference.

All of the remaining citation methods are linked to specific assertions in the article and all of them are preferable to this method.

Parenthetical citations using plain text

A parenthetical reference is a short source citation that appears in parentheses in the article text after the assertion(s) that it supports. There are various styles for the short source citation; I recommend including the surname of the author(s), the year of publication, and the page numbers associated with this specific reference.

To add a parenthetical reference:

1. Key the short source citation text in parentheses after the assertion that it supports.
2. If the article does not have a References section, add one.
3. If the source is not in the References list already, add a full source citation entry to the list of references.

Parenthetical citations are relatively simple to specify and are a significant improvement compared to a general reference. The parenthetical reference clutters the text, but proponents argue that a reader familiar with the topic may recognize a citation without having to check in the references section and can assess the reliability of the source more quickly than using a number to find an entry in the footnotes. For a longer list of pros and cons, see the parenthetical referencing article.

Parenthetical references are not the best choice for most Wikipedia articles. In a web context where a footnote number is a clickable link, it's easy for the reader to access the full details of the footnote without cluttering the article with the short footnote details.

Parenthetical citations using templates

Wikipedia provides templates to help editors implement parenthetical citations. Using the templates improves the consistency of the citations and provides other benefits to the reader such as links between the parenthetical citation and the full citation in the footnotes. It's beyond the scope of this page to describe all the templates but I will provide an example of using the " Harvard" style of parenthetical references. See the WP:Parenthetical referencing article for more information.

To add a "Harvard" style parenthetical reference using templates:

1. Key the short source citation text using the {{ Harv}} template after the assertion that it supports.
2. If the article does not have a References section, add one.
3. If the source is not in the References list already, add a full source citation entry to the list of references using the appropriate citation template.

This example demonstrates two templates that work together, {{Harv}} to create the short footnote and {{cite book}} to create the full footnote in the References section. {{Harv}} is relatively simple to use; you specify the surname(s) of the authors, the year of publication, and the page number(s). {{cite book}} creates the full footnote in the References section.

Using the templates improves the consistency of the short footnote and full footnote, and the template provides an extra benefit of creating an on-page link in the short footnote that scrolls the page and highlights the associated full footnote. In order for the link to work, the {{cite book}} template must include the |ref=harv parameter.

Footnote citations using plain text

In a footnote-based citation system, source citations are added as footnotes near the bottom of the page. A footnote number in brackets follows the assertion the citation supports. Using a footnote reduces the clutter in the article.

Wikipedia provides the REF and REFERENCES elements to coordinate the creation of footnote numbers and the associated footnote text. In the article text, the REF and REFERENCES elements look like HTML tags but they are not HTML.

To add a footnote reference:

1. Key the REF element after the assertion that it supports.
2. If the article does not have a Notes section, add one following the model shown in the example.

The REF element creates the footnote number and link automatically. The footnote text is specified between the <ref> and </ref> tags. The REFERENCES element creates the list of footnotes. It has no content, so it is usually specified using a "self-closing" notation where the tag ends with a "/>". The list automatically includes carets (up arrows) that are on-page links that scroll the page to where the footnote number appears.

Using source footnotes reduces clutter in the article, but it increases clutter in the editable article text: the REF element and its contents interrupt the article content.

If the exact same source citation supports more than one assertion in the article you may use the |name= parameter on the REF element to avoid specifying the source citation twice.

To add a footnote reference that supports more than one assertion:

1. Key the REF element after the first assertion that it supports. Specify a unique value for the |name= parameter.
2. Key the REF element after the subsequent assertion(s) that supported by the same source citation. Use the same value for the |name= parameter as you specified in step one.
3. If the article does not have a Notes section, add one following the model shown in the example.

The first reference to the source citation for page 3 of the John Doe book includes the |name=doe1857p3 parameter. That assigns a name to the given source citation. The second reference to that same citation (which is the third source reference overall) specifies the same name value and does not specify any content. In the list of footnotes, item number one has two clickable links, A and B, one for each reference to that source citation.

In this example, I've replaced <references/> with {{ Reflist}}. {{Reflist}} is a template that wraps the <references/> tag with formatting that improves the appearance of the references list. I will continue to use it in all of the remaining examples.

So far, the examples have used a bare-bones source citation for the John Doe book. A complete source citation for such a book would include the publisher, publisher location, and ISBN number. Let's expand the example to include that information and help illustrate how inline citations clutter the article text.

Footnote citations using templates

As described above there are benefits to using citation templates rather than creating the footnote text by hand. Example 7 below is the same as Example 6 except that the footnote text is created using the {{cite book}} template.

While there are benefits of using citation templates, they add clutter to the article text and thus make it more difficult to edit the prose. If you compare Example 7 to Example 2 you will see that the article text has expanded dramatically while the visible content in the article hasn't changed much. The citations in Example 7 are complete and provide useful features such as links between the footnote numbers and the footnotes, but the article has become harder to maintain.

Short footnote citations using Sfn and templates

There are various methods for creating short footnotes that reduce the clutter in the article text yet provide the same (or a better) outcome as the best results shown above. The key is to combine these two techniques:

1. Use short footnotes linked to a Notes section.
2. Link the short footnotes in the Notes section to full footnotes in a References section.

A shortcut that reduces the difficulty of maintaining the page is to use the {{ Sfn}} template to create the short footnotes. The {{Sfn}} template uses a terse syntax to create the short footnote content and automates the creation of the REF element. In so doing, it eliminates the need to manage unique values for the |name= parameter of the REF element.

The parameters for {{Sfn}} mimic the short footnote content used in the parenthetical references described above; author surname(s), year of publication, and page number(s). The resulting template call is approximately the same length as the plain text version and reduces the interruption of the article text to a minimum.

To add a footnote using the {{Sfn}} template:

1. Add the {{Sfn}} template after the assertion the citation supports.
2. If the article does not have a Notes section, add one following the model shown in the example.
3. If the article does not have a References section, add one following the model shown in the example.
4. If the source is not in the References list already, add a full source citation entry to the list of references using the appropriate citation template. Add the |ref=harv parameter to the citation template.

If you compare Example 8 to Example 7 you will see that the clutter in the article text has been reduced dramatically, mostly by moving the citation details from the article body to the References section. If you click on the "Doe 1857" link in the Notes section, the browser will scroll to the full footnote associated with that note (if it is not visible) and highlight it.

Challenges using short footnotes

Missing or unknown source details and other issues may cause ambiguous references when using {{Sfn}}.

Missing author name

Some sources do not identify an author, including news stories with no byline. The usual solution is to use the name of the organization associated with the source, such as the name of the publisher, newspaper, magazine, journal, or web site.

Missing date

Some sources do not include an explicit date from which to extract a year. For a copyrighted work, one solution is to use the copyright date. When no copyright date is available, use the year from the access date.

Multiple works in the same year

When you cite two or more works published by an author in a single year, the combination of the author name and publication year is ambiguous. For all the works by the same author(s) in a single year, append a lowercase alphabetic suffix, a, b, c, etc., to the year. For example, if John Doe published two books in 1985, the first would be coded with |year=1985a, the second with |year=1985b.

When using the technique described above for dealing with a missing author name, the link target created by the |ref=harv parameter on the full footnote citation will not match the ID created by the {{Sfn}} template. The solution is to use the {{ SfnRef}} template to create the proper value. Pass the same arguments to {{SfnRef}} as specified for the {{Sfn}} template.

Here's an example using a fictitious article published on a web site.

Summary