Stock car racing:Citing sources

A citation is a line of text that uniquely identifies a source. For example: It allows a reader to find the source and verify that it supports material in.

When to use. As described in the When to cite sources section of this guideline, sources should be cited when adding material that is challenged or likely to be challenged, when quoting someone, when adding material to the biography of a living person, when checking content added by others, and when uploading an image.

How to format. While you should attempt to format a citation as described in the How to format citations section of this guideline, it is even more important that material in is verifiable. Add your source even if you are unsure of how to properly format the citation—provide enough information to identify the source, and others will improve the formatting.

How to present. Citations are usually presented within articles using one of the methods described in the How to present citations section of this guideline. Each article should use the same method throughout—if an article already has some citations, an editor should adopt the method already in use or seek consensus before changing it.

Footnote summary
The most common method for citing sources in Wikipedia uses footnotes. The basic steps are:


 * Immediately after the text that requires a source, add  . This will appear as a numbered superscript link.
 * If you are working on a new page, or adding the first footnote to a page, add the following wiki markup at the bottom of the page, where the body of the footnote will appear:
 * {| style="background:transparent;"


 * ==Notes==
 * ==Notes==

which appears as:


 * Plunkett, John. "Sorrell accuses Murdoch of panic buying", The Guardian, October 27, 2005.

Because of the difficulties in associating them with their appropriate full citations, the use of embedded links for inline citations is not particularly recommended as a method of best practice and is not found in featured articles. It is easily converted to a shortened footnote or parenthetical reference.

Avoid scrolling lists
Scrolling lists, for example lists of citations appearing within a scroll box, should never be used because of issues with readability, accessibility, printing, and site mirroring. Additionally, it cannot be guaranteed that such lists will display properly in all web browsers.

See this July 2007 policy discussion for more detail.

Collapsible tables
Footnotes and/or citations with collapsible tables, see example below, are an uncommon format. Nevertheless, the tables can be useful for implementing a dual reference system, whereby one citation table may be sorted in alphabetical order by title and the other table may be sorted by origin. Unlike scrolling lists, collapsible tables function properly with footnotes/citations and may be easily printable. Though it is possible, the collapsible table is uncommonly used in conjunction with regular footnotes for annotation purposes.

  The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.

&#61;= References ==



Unsourced material
If an article has no references, and you are unable to find them yourself, you can tag the article with the template Unreferenced, so long as the article is not nonsensical or a biography of a living person, in which case request admin assistance. If a particular claim in an article lacks citation and is doubtful, consider placing fact after the sentence or removing it. This will add a citation needed label.

Consider the following in deciding which action to take:


 * If a claim is doubtful but not harmful to the whole article or to, use the fact tag, but remember to go back and remove the claim if no source is produced within a reasonable time.


 * If a claim is doubtful and harmful, you should remove it from the article; you may want to move it to the talk page and ask for a source, unless you regard it as very harmful or absurd, in which case it should not be posted to a talk page either. Use your common sense. All unsourced and poorly sourced contentious material about living persons should be removed from articles and talk pages immediately. It should not be tagged. See Biographies of living persons and Libel.

Preventing dead links
To help prevent dead links, persistent identifiers are available for some sources. Some journal articles have a digital object identifier (DOI); some online newspapers and blogs, and also, have permalinks that are stable. When permanent links aren't available, consider archiving the referenced document when writing the article; on-demand web archiving services such as WebCite (http://www.webcitation.org) are fairly easy to use (see pre-emptive archiving).

Repairing dead links
Dead links should be repaired or replaced if possible. In most cases one of the following approaches will give an acceptable alternative.


 * First, check the link to confirm that it is dead. The site may have been temporarily down or have changed its linking structure. If the link has returned to service but has been labeled as a dead link, simply remove the labeling. See dead link.
 * If the document is no longer available at the original website, there may be a copy of the referenced document at a web archiving service. If so, update the citation to include a link to the archived copy of the referenced document.
 * The Internet Archive (http://www.archive.org/) has literally billions of archived webpages. Note that there may be a delay of six months before a recent link shows up there. See also the article Using the Wayback Machine.
 * WebCite is an "on-demand" archiving service (http://www.webcitation.org) that should also be checked.
 * If a good copy of the original document cannot be located, it may be possible to find a substitute. Enter key words or phrases or other content from the cited material into the referenced website's search engine, into a similar website's search engine, or into a general search engine such as Google.  (A search engine may hold a cached version of the dead link for a short time, which can help find a substitute.)  Or, browse the referenced document's website or similar websites.  If you find a new document that can serve as a substitute, update the dead link to refer to the new document.
 * Deactivate the dead link, and keep the citation information if still appropriate to the article. (This may happen, for example, when an online copy of material that originally appeared in print is no longer online.)  In the remaining citation, note that the dead link was found to be inactive on today's date. Even with an inactive link, the citation still records a source that was used, and provides a context for understanding archiving delays or for taking other actions.  In order to deactivate the dead link, do one of the following.
 * Turn the dead link into plain text. Remove only enough of the dead link's wikitext or markup language or URI scheme (square brackets, "http://", and so on) so that clicking on the link does not take you to its destination. This will make the link visible to both readers and editors of the article.
 * Turn the dead link into an HTML comment. Place HTML comment markup language around the link.  This will make the link disappear when reading the article, but will preserve the link for editors of the article.

If a dead link cannot be repaired or replaced, consider reworking the article section so that it no longer relies on the dead link.

Whether a dead link can or cannot be repaired or replaced, remember that Wikipedia policy (including policy on sources and biographies of living persons) still applies. Consider doing further edits of the citation and cited material, if appropriate, to improve the article.

Use of terms
A "citation" is a line of text that identifies a source. A "source" (for the purposes of this guideline) is a document (or webpage) that is used to support material in an article. The word "reference" may refer to the citation, to the source or to both together.

A common system of citation on is a footnote system, where citations appear in footnotes. A footnote containing a citation is a "reference", a "citation" and a "footnote" at the same time.

The terms Footnote and Note are also used interchangeably. There is no separate usage of the term "Endnote" because each article, like other HTML documents, is considered to be only one page even if it is displayed across several screens.

The terms Further Reading, External links or Bibliography are used as section headings in articles for lists of additional general texts on a topic for those interested, rather than for citations supporting the article.

Citation creation tools
A wide range of tools is available to help put together a full citation.

Citation processing tools

 * – tool for finding article-level citation errors and fixing them. Not currently functional.
 * Citation bot (formerly DOI bot) – automatically fixes common errors in individual citations, and adds missing fields

Programming tools

 * Wikicite is a free program that helps editors to create citations for their contributions using citation templates. It is written in Visual Basic .NET, making it suitable only for users with the .NET Framework installed on Windows, or, for other platforms, the Mono alternative framework. Wikicite and its source code is freely available, see the  for further details.
 * is a program based on the original Wikicite source code. It features extra validation, bug fixes, additional cite templates (such as cite episode) as well as tools for stub sorting and more. It is also available for free under the Apache License 2.0 and is open source.
 * pubmed2wiki.xsl a good stylesheet transforming the XML output of  to refs.
 * has tools to automatically handle citations for a whole article at a time. Converts occurrences of or  to properly formatted footnote or Harvard style references. Written in  and requires a working installation with basic libraries.

Citation export tools
You can insert a link beside each citation in, allowing you to export the citation to a reference manager such as. Just copy this code: importScript("User:Smith609/endnote.js"); to the end of Special:MyPage/monobook.js. Then, save the page and press Ctrl-F5 to clear your browser's cache.