WP:CITE

:WP:CITE, WP:REF, and WP:CS redirect here. You may also be looking for Wikipedia:Citing Wikipedia, Wikipedia:Reference desk, Wikipedia:Cheatsheet, WikiProject Computer science or WikiProject Coronation Street. For citation templates, see WP:CIT.
A citation is a line of text that uniquely identifies a source. For example:
:*Ritter, Ron. The Oxford Style Manual, Oxford University Press, 2002, p. 1.
 
When to cite sources: The policy on sourcing is Wikipedia:Verifiability, which requires inline citations for any material challenged or likely to be challenged, and for all quotations. The policy is strictly applied to all material in the mainspace—articles, lists, and sections of articles—without exception, and in particular to information about living persons: unsourced contentious or negative material about living persons must be removed immediately. When an image is uploaded, the uploader must state where the image came from, and its copyright status. If the image comes from an online site, a link to the source page is normally provided.
How to write citations: While you should try to write citations correctly, what matters is that you add your source—provide enough information to identify the source, and others will improve the formatting if needed. Each article should use the same citation method throughout. If an article already has citations, adopt the method in use or seek consensus before changing it.
In the event of a contradiction between this page and the sourcing policy, Wikipedia:Verifiability, the policy takes priority, and this page should be updated to reflect it.
==Use of terms==
A "citation" is a line of text that identifies a source. The word "source" has three related meanings on Wikipedia: the piece of work itself, the creator of the work, and the publisher of the work; see Wikipedia:Verifiability#Reliable sources. The word "reference" may refer to the citation, the source, or both.On Princeton's WordNet one of the definitions of "to cite" is "to make reference to". (See the entry halfway down the page here and note that it also explicitly lists "reference" as a synonym for "cite".)
A common system of citation on Wikipedia is a footnote system, where citations appear in footnotes. The terms "footnote" and "note" are used interchangeably. There is no separate usage of the term "endnote," because each Wikipedia article, like other HTML documents, is considered to be only one page even if it is displayed across several screens. The terms "Further reading" and "External links" are used as section headings for lists of additional general texts on a topic for those interested.
==Summary==
Footnote referencing is the most common method for citing sources in Wikipedia. The basic steps are:
* Ensure that the following wiki markup is at the bottom of the page - if not enter it (the alternative titles "References" or "Footnotes" may be used rather than "Notes"):
:
==Notes== <references />	OR	==Notes==
* Immediately after the material in the text that requires citation, add:
:<ref>details of the source</ref>
 
It is usually sufficient to add footnotes after the sentence or paragraph to which the citation applies. If the issue is very contentious, footnotes can be added immediately after the word or clause they support. Follow the punctuation style established in the article, but normally the footnote is placed immediately after any punctuation marks that directly follow the word, clause, or sentence.
* When the page is previewed or saved, the footnote number will automatically appear in the position of the <ref> .. </ref> markup, and the citation will appear in a numbered list in the "Notes" (or "Footnotes") section. Clicking on the numbered superscript in the text will take you to the footnote in the list.
==Why and when to cite sources==
Wikipedia is written by contributors with a wide range of knowledge and skills. Readers need to be able to check the contributors' sources. Adding citations (references):
*Ensures that the content of articles can be checked by any reader or editor;
*Shows that your edit is not original research, reducing editorial disputes;
*Avoids claims of plagiarism and copying;
*Helps users find additional information on the topic;
*Ensures that material about living persons complies with biography policy;
*Improves the credibility of Wikipedia;
===When adding material that is challenged or likely to be challenged===
Wikipedia:Verifiability says: "All quotations and any material challenged or likely to be challenged should be attributed to a reliable, published source using an inline citation."
The need for citations is especially important when writing about opinions held on a particular issue. Avoid weasel words where possible, such as, "Some people say ..." Instead, make your writing verifiable: find a specific person or group who holds that opinion and give a citation to a reputable publication in which they express that opinion. Remember that Wikipedia is not a place for expressing your own opinions or for original research. Opinions, data and statistics, and statements based on someone's scientific work should be cited and attributed to their authors in the text.
===When quoting someone===
:For information on the formatting and treatment of quotations, see Manual of Style:Quotations
You should always add a citation when quoting published material, including the page number if there is one. The citation should be placed either directly after the quotation
:Example: 
or after a sentence or phrase that introduces the quotation.
:Example: 
For statements about which reliable sources are in conflict, the text should clearly attribute the opinions.
:Example: 
===When writing about living persons===
Statements about living persons should be sourced with particular care, for legal and ethical reasons. All contentious material about living persons must cite a reliable source. If you find unsourced or poorly sourced contentious material about a living person, whether in an article or on a talk page, remove it immediately! Do not leave it in the article while you request a source. Do not move it to the talk page. This applies whether the material is in a biography or any other article.
===When checking content added by others===
You can also add sources for material you did not write. Adding citations is an excellent way to contribute to Wikipedia. See Wikipedia:WikiProject Fact and Reference Check for organized efforts to add citations.
====Dealing with unsourced material====
If an article has no references, and you are unable to find any yourself, you can tag the article with the template , so long as it is not nonsensical or a biography of a living person, in which case request admin assistance.
* If a claim is doubtful but not harmful, use the tag, which will add "citation needed," 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 it is very harmful or absurd, in which case it should not be posted to the 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. See Wikipedia:Biographies of living persons and Wikipedia:Libel.
===When writing an image caption===
Image captions within articles, also known as cutlines, should be referenced, if needed, just like any other part of the text.
===When uploading an image===
Images must include source details and a copyright tag on the image description page. It is important that you list the author of the image if known (especially if different from the source), which is important both for copyright and for informational purposes. Some copyright licenses require that the original author receive credit for their work. 
*If you download an image from the web, you should give the URL:
:Example: 
*If you got the image from an offline source, you should specify:
:Example: 
Any image with a non-free copyright license must be accompanied by a non-free use rationale (also called a fair use rationale) for each article in which the image is used.
==How to present citations==
Citations are usually presented within articles in one of five ways: 
#General reference: By placing the citation in a list at the end of an article.
#Footnote: By placing it in a footnote, with a link following the assertion (whether a clause, sentence, paragraph, etc.) that it supports.Ritter, R. (2002). The Oxford Style Manual. Oxford University Press, p. 45. ISBN 0198605641.
#Shortened footnote: By placing the citation in the list and naming only the author, year, and page number in a footnote.<ref>Ritter 2002, p. 45.
#Parenthetical reference: By placing the citation in the list and naming the author, year, and page number in parentheses (Ritter 2002, p. 45).
#Embedded links may be used if the source is a web page.
Editors are free to use any method; no method is preferred over another, though the use of embedded links for inline citations is not considered best practice and is not found in featured articles. Some articles use a combination of general references, citations in footnotes and shortened notes. (See, for example, Starship Troopers, Rosa Parks or Absinthe.) Some articles use separate sections for footnotes containing citations and other footnotes. (See Augustus.)
Sections containing citations are usually called "Notes" or "References." Many editors prefer to reserve the section heading "Bibliography" for complete lists of published works in authors' biographies. Whichever header you choose, sections containing citations should be placed after the "See also" section and before the "Further reading" section.For more information see Wikipedia:Layout#standard appendices Once a style is selected for an article it is inappropriate to change to another, unless there is a reason that goes beyond mere choice of style.For more information see WP:Manual of Style#Consistency.
===General reference===
If a source supports a significant amount of the material in an article, it may sometimes be acceptable to simply add the citation at the end. It serves as a general reference, not linked to any particular part of the article. This is more likely to be appropriate for relatively undeveloped articles or those covering a very simple or narrow topic. Any material challenged or likely to be challenged requires an inline citation, as does contentious material about a living person; see above. 
The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.
== References ==
*Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
*Miller, E (2005). The Sun, Academic Press.</span>
Below is how this would look once the edit has been saved (note book/magazine titles italicized):
The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.
References
----
*Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
*Miller, E (2005). The Sun, Academic Press.
===Inline citations===
In most cases, an inline citation is required, either in addition to, or instead of, a full citation in the References section, depending on which citation method is being used (see below). Inline citations show which specific part of the article a citation is being applied to. They are required by Wikipedia's verifiability policy for statements that are challenged or likely to be challenged, including contentious material about living persons, and for all direct quotations. Inline citations are also mandated by Wikipedia's featured article criteria, where appropriate. An inline citation should appear next to the material it supports. If the material is particularly contentious, the citation may be added within a sentence, but adding it to the end of the sentence or paragraph is usually sufficient. If the same material occurs more than once, the citation should ideally be placed next to the first occurrence. The following methods of inline citation are used in Wikipedia:
====Footnotes====
Many Wikipedia articles, particularly the more developed articles and those which meet good or featured article criteria, place their citations in footnotes. The inline citations in this method appear as small clickable numbers within the text, which link to a numbered list of full citations in footnotes at the end of the article.
For a citation to appear in a footnote, it needs to be enclosed in "ref" tags. You can add these by typing <ref> at the front of the citation and </ref> at the end. Alternatively you may notice below the edit box there is a list of "markup" which includes <ref></ref> – if you highlight your whole citation and then click this markup, it will automatically enclose your citation in ref tags. Optionally, one may add the name attribute by using <ref name="name">details of the citation</ref>. Thereafter, the same footnote may be used multiple times by adding <ref name="name"/>. Some names require the use of straight quotation marks, and it is never wrong to use them.
The full citation will appear in an appendix to the article. If this appendix does not already exist, create the appendix and place either <references/> or in it.See Wikipedia:Layout#Notes and References for information regarding where to place the new appendix in the article. This will automatically generate the list of footnotes.
The example below shows what this would look like in the edit box:
The Sun is pretty big,<ref>Miller, E: The Sun, page 23. Academic Press, 2005.</ref>
but the Moon is not so big.<ref>Brown, R: "Size of the Moon", Scientific American, 51(78):46</ref>
The Sun is also quite hot.<ref>Miller, E: The Sun, page 34. Academic Press, 2005.</ref>
==Notes==
<references/>
Below is how this would look in the article, once you had previewed or saved your edited section:
The Sun is pretty big,[1] but the Moon is not so big.[2] The Sun is also quite hot.[3]
Notes
----
^ Miller, E: The Sun, page 23. Academic Press, 2005.
^ Brown, R: "Size of the Moon", Scientific American, 51(78):46.
^ Miller, E: The Sun, page 34. Academic Press, 2005.
Where the issues are not contentious, you can combine references to avoid clutter:
The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.[1]
Notes
----
^ For the Sun's size, see Miller, E: The Sun, page 23. Academic Press, 2005. For the Moon's size, see Brown, R: "Size of the Moon", Scientific American, 51(78):46. For the Sun's heat, see Miller, E: The Sun, page 34. Academic Press, 2005.
=====Shortened footnotes=====
Many articles use shortened citations in footnotes, giving just the author, year (or title) and the page numbers. As before, the list of footnotes is automatically generated in a "Notes" or "Footnotes" section. A full citation is then added in a "References" section. The short citation and the full citation may be linked so that the reader may click on the short note to highlight the full citation (see wikilinks to full references). Short citations can be written manually, or by using the or templates, though note that templates should not be added without consensus to an article that already uses a consistent referencing style.
Shortened footnotes are used for several reasons: they allow the editor to cite many different pages of the same source without having to copy the entire citation; they avoid the inevitable clutter when long citations are inserted into the source text; they bring together all the full citations into a coherent block of code (rather than being strewn throughout the text) which allows the list to be alphabetized and makes it easier to edit all the full citations at once (e.g., adding ISBN, DOI or other detail); and a single footnote can contain multiple citations, thus avoiding long rows of footnote markers. 
Below is an edit-mode view of short footnotes:
The Sun is pretty big,<ref>Miller 2005, p. 23.</ref>
but the Moon is not so big.<ref>Brown 2006, p. 46.</ref>
The Sun is also quite hot.<ref>Miller 2005, p. 34.</ref>
== Notes ==
{{Reflist|2}}
== References ==
*Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
*Miller, E (2005). The Sun, Academic Press.</span>
Below is how this would look once the edit has been saved:
The Sun is pretty big,[1] but the Moon is not so big.[2] The Sun is also quite hot.[3]
Notes
----
^ Miller 2005, p. 23.
^ Brown 2006, p. 46.
^ Miller 2005, p. 34.
References
----
*Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
*Miller, E (2005). The Sun, Academic Press.
Shortened notes using titles rather than publication dates could look like this in the article:
Notes
----
^ Miller, The Sun, p. 23.
^ Brown, "Size of the Moon", p. 46.
^ Miller, The Sun, p. 34.
For more detailed examples using shortened notes, including the use of links from the short notes to the full references, see Wikipedia:Citing sources/Example edits for different methods.
===== List-defined references =====
As of September 2009, the Cite.php extension was modified to suport list-defined references. These can be implemented with the parameter to the template, or by using a pair of HTML tags (<references> and </references>) in place of the <references/> tag. These reduce clutter within articles, by putting all the citation details in the section at the end where the footnotes are displayed. As with other citation formats, these should not be added to articles that already have a stable referencing system, unless there is consensus to do so. When in doubt, use the referencing system added by the first major contributor to use a consistent style.
The example below shows what list-defined references look like in the edit box:
The Sun is pretty big,<ref name=Miller2005p23/>
but the Moon is not so big.<ref name=Brown2006/>
The Sun is also quite hot.<ref name=Miller2005p34/>
==Notes==
{{reflist|refs=
<ref name=Miller2005p23>Miller, E: The Sun, page 23. Academic Press, 2005.</ref>
<ref name=Miller2005p34>Miller, E: The Sun, page 34. Academic Press, 2005.</ref>
<ref name=Brown2006>Brown, R: "Size of the Moon", Scientific American, 51(78):46</ref>
}}
Below is how this would look in the article, once you had previewed or saved your edited section:
The Sun is pretty big,[1] but the Moon is not so big.[2] The Sun is also quite hot.[3]
Notes
----
^ Miller, E: The Sun, page 23. Academic Press, 2005.
^ Brown, R: "Size of the Moon", Scientific American, 51(78):46.
^ Miller, E: The Sun, page 34. Academic Press, 2005.
Defined references must be used within the body; unused references will show an error message. However, non-list-defined references (i.e. ordinary footnote references fully enclosed with <ref> and </ref> tags) will display as normal along with any list-defined ones.
====Parenthetical referencing====
Two forms of parenthetical referencing may also be used in Wikipedia: author-date referencing (APA style, Harvard style, or Chicago style); and author-title or author-page referencing (MLA style or Chicago style). For a discussion of the advantages and disadvantages, see Pros & Cons.
In parenthetical citations, a short version of the citation is added in parentheses just after the point it is supporting, comprising only the surname of the author(s) and the year of publication, and possibly page numbers (APA style); or the surname of the author(s) and possibly short titles and/or page numbers (MLA style).
Using author-date parenthetical references, the inline citation usually looks like: (Author 2006:28) or (Author 2006, p. 28). The full citation is then added at the end of the article to a "References" or "Works cited" section. This list of full citations is usually ordered alphabetically by author name. As with shortened notes, the inline citation and the full citation may be linked so that the reader may click on the inline citation to highlight the full citation (see linking inline and full citations).
Below is an edit-mode view of adding author-date citations to an article:
The Sun is pretty big (Miller 2005),
but the Moon is not so big (Brown 2006, p. 46).
The Sun is also quite hot (Miller 2005, p. 34).
== References ==
*Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
*Miller, E (2005). The Sun, Academic Press.</span>
Below is how this would look once the edit has been saved:
The Sun is pretty big (Miller 2005), but the Moon is not so big (Brown 2006, p. 46). The Sun is also quite hot (Miller 2005, p. 34).
References
----
*Brown, R (2006). "Size of the Moon", Scientific American, 51(78).
*Miller, E (2005). The Sun, Academic Press.
====Embedded links====
If a webpage is used as a source, it can be linked to directly within the article by enclosing the URL in square brackets just after the point it is supporting. When the edit is saved, only a number is visible within the text. For example, a citation of a newspaper article can be embedded by adding , which looks like 
Embedded links should not be used to place external links to websites in the body of an article where they are not used to verify article content, but instead to direct readers to other websites. For example, do not spam links to companies' or organizations' websites in article text, like this: "Apple, Inc. announced their latest product..." Only links to pages that directly support claims made in the article should be embedded as links, and those embedded links should follow the formatting shown in the previous paragraph. InterWikimedia links to Wiktionary and Wikisource are sometimes appropriate in the body of an article; for details, see Wikipedia:Wikimedia sister projects.
A full citation is also required in a References section at the end of the article. For example:
*Plunkett, John. "Sorrell accuses Murdoch of panic buying", The Guardian, London, October 27, 2005.
which appears as:
*Plunkett, John. "Sorrell accuses Murdoch of panic buying", The Guardian, London, 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 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.
===Say where you found it===
It is improper to take material from one source and attribute it to a different one. For example, a webpage may provide information that the page's author attributes to a book. Unless you examine the book yourself, your source is the webpage, not the book. You should also make clear, where appropriate, that the webpage cited the book. It can be important to be clear about this for two reasons: (a) because the credibility of your edit rests on the webpage, which may have misinterpreted the book, and (b) because it is sometimes preferable to cite the original source, especially where the issue is a contentious one. 
For example, where Smith is the author of the book, and Jones the author of the webpage you have read, you could write: "Smith 2005, p. 100, cited in Jones 2010," between ref tags, with full citations in the References section. Or if you're using long citations in the text, you could write, again between ref tags: "Smith, John (2005). Name of Book. Cambridge University Press, p. 100, cited in Jones, Paul (2010). "About Me," Pauljones.com, accessed January 15, 2010. Note that it is always better to read the original source material yourself.
===Non-English sources===
Because this is the English Wikipedia, English-language sources should be used in preference to non-English language sources of equal caliber and content, though the latter are allowed where appropriate. When quoting a source in a different language, please provide both the original-language quotation and an English translation, in the text, in a footnote, or on the talk page as appropriate.
===Convenience links===
A convenience link is a link to a copy of your source on a webpage provided by someone other than the original publisher or author. For example, a copy of a newspaper article no longer available on the newspaper's website may be hosted elsewhere. When offering convenience links, it is important to be reasonably certain that the convenience copy is a true copy of the original, without any changes or inappropriate commentary, and that it does not infringe the original publisher's copyright. Accuracy can be assumed when the hosting website appears reliable. Where several sites host a copy of the material, the site selected as the convenience link should be the one whose general content appears most in line with Wikipedia:Neutral point of view and Wikipedia:Verifiability.
===Multimedia===
Multimedia material should be referenced just like article text. Citations for a media file should appear on its file page. Image captions should be referenced as appropriate just like any other part of the article. If an infobox or table contains text that needs citing, but the box or table cannot incorporate an inline citation, the citation should appear in a caption or other text that discusses the material. A citation is not needed for descriptions such as alt text that are verifiable directly from the image itself. Material that identifies a source (e.g., the caption "Belshazzar's Feast (1635)" for :File:Rembrandt-Belsazar.jpg) is considered attribution and normally does not need further citation.
===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 discussion for more detail.
==How to format citations==
===Consistent style===
Citations in Wikipedia articles should use a consistent style. Any of the following styles are acceptable so long as each article is internally consistent. You should follow the style already established in an article, if it has one; where there is disagreement, the style used by the first editor to use one should be respected.
Similarly, there are several methods of internal formatting or markup that can used to create a given displayed citation. The best practice is for a given article to be consistent in internal markup or formatting. It is better to follow the patterns in place if an article has a stable citation structure. Changing existing citations from one format to another should generally be done only with local consensus, and should never be the subject of an edit war. 
However, if an editor can provide a new relevant reference, either to new content or to existing unsourced content, it is more important for the citation to the reference to be recorded in some format. Another editor can always edit the reference to bring it into consistency with the style and formatting of the existing citations in the article.
===Citation styles===
There are a number of citation styles. See here for some examples. They all include the same information but vary in punctuation and the order of the author's name, publication date, title, and page numbers. 
Full citations for books typically include: 
*name of the author(s)
*year of publication in brackets
*title of the book in italics
*city of publication optional 
*name of the publisher
*page number(s) where appropriate 
*ISBN optional 
:Full citations for individually authored chapters in books additionally include:
:*the book's overall editor
:*the title of the chapter
:*the page numbers for the chapter
Full citations for journal articles typically include:
*name of the author(s)
*year and sometimes month of publication
*title of the article within quotation marks
*name of the journal in italics
*volume number, issue number (if the journal uses them), and page numbers (article numbers in some electronic journals)
Citations for newspaper articles typically include:
*name of the newspaper in italics (required)
*date of publication (required)
*byline (author's name), if any 
*title of the article within quotation marks
*city of publication, if not included in name of newspaper
*page number(s) are optional
Citations for World Wide Web articles typically include:
*name of the author(s)
*title of the article within quotation marks
*name of the website (linked to a Wikipedia article about the site if it exists, or to Website's "about" page)
*date of publication 
*page number(s) (if applicable)
*the date you retrieved it (required if the publication date is unknown)
===Identifying parts of a source===
You should identify any part of a source that you quote, paraphrase or cite; in the case of a book, specify the page number(s). It is also important to specify the version (date and edition for books) of the source because the layout, pagination, length, etc can change. Page numbers are especially important for lengthy non-indexed books, but they are not required for a reference to the source as a whole; for example when describing a complete book or article or when the source is used to illustrate a particular point of view.
===Links and ID numbers===
A citation ideally includes a link or ID number to help editors locate the source. If you have a URL (webpage) link, you can add it to the title part of the citation, so that when you add the citation to Wikipedia the URL becomes hidden and the title becomes clickable. To do this, enclose the URL and the title in square brackets—the URL first, then a space, then the title. For example: 
Carr A, Ory D (2006). Does HIV cause cardiovascular disease? PLoS Medicine, 3(11):e496.
For web-only sources with no publication date you should include a "Retrieved" date instead, in case the webpage changes in the future. For example: 
You can also add an ID number to the end of a citation. The ID number might be an ISBN for a book, a DOI (Digital Object Identifier) for an article, or any of several ID numbers that are specific to particular article databases, such as a PMID number for articles on PubMed. It may be possible to format these so that they are automatically activated and become clickable when added to Wikipedia, for example by typing ISBN (or PMID) following by a space followed by the ID number.
If your source is not available online, it should be available in reputable libraries, archives, or collections. If a citation without an external link is challenged as unavailable, any of the following is sufficient to show the material to be reasonably available (though not necessarily reliable): providing an ISBN or OCLC number; linking to an established Wikipedia article about the source (the work, its author, or its publisher); or directly quoting the material on the talk page, briefly and in context.
==Citation templates and tools==
:For a comparison of citations using templates with citations written freehand, see Wikipedia:Citing sources/Example edits for different methods.
Citation templates are used to format citations in a consistent way. The use of citation templates is neither encouraged nor discouraged. Templates may be used or removed at the discretion of individual editors, subject to agreement with other editors on the article. Because templates can be contentious, editors should not change an article with a distinctive citation format to another without gaining consensus. Where no agreement can be reached, defer to the style used by the first major contributor.
There are several webpages/tools that can help quickly produce a citation in a standard template format. You may only need one piece of information and they can fill in the rest of the details. The resulting citation will be enclosed in "cite" tags, and it will be formatted in a particular way depending on which kind of template is being used. You can then copy all the text from there. It may still require additional tags before you can add it to a Wikipedia article. 
===Metadata===
Citations may be accompanied by metadata, though it is not mandatory. Most citation templates on Wikipedia use the COinS microformat. Metadata such as this allow browser plugins and other automated software to make citation data accessible to the user, for instance by providing links to their library's online copies of the cited works. In articles that format citations manually, metadata may be added manually in a span, according to the COinS specification; or the templates Template:Citation metadata or Template:COinS can be used.
===Citation processing tools===
* Template:Citation/core – a core template used by other citation templates
* User:CitationTool – a tool for finding article-level citation errors and fixing them. Not currently functional.
* Citation bot (formerly DOI bot) – a bot that 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 Wikipedia 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 developer's page for further details.
** Wikicite+ 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 XSL stylesheet transforming the XML output of PubMed to Wikipedia refs.
* User:Richiez has tools to automatically handle citations for a whole article at a time. Converts occurrences of {{pmid XXXX}} or {{isbn XXXX}} to properly formatted footnote or Harvard style references. Written in ruby and requires a working installation with basic libraries.
* RefTag by Apoc2400 creates a prefilled template with various options from a Google Books URL. The page provides a bookmarklet for single-click transfer.
===Citation export tools===
You can insert a link beside each citation in Wikipedia, allowing you to export the citation to a reference manager such as EndNote. Just copy this code:
importScript("User:Smith609/endnote.js");
to the end of Special:MyPage/monobook.js. Then, save the page and bypass your browser's cache.
==Preventing and repairing 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 Wikipedia, 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).
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 .
*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 Wikipedia: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, one option to consider is reworking the article section so that it no longer relies on the dead link, though this is not required. Regardless of 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.
==See also==
How to cite
* Wikipedia:Verification methods – listing examples of the most common ways that citations are used in Wikipedia articles.
* Wikipedia:Citing sources/example style – listing examples of full citations using APA and Harvard referencing techniques.
* Wikipedia:Citing sources/Example edits for different methods – showing comparative edit mode representations for different citation methods and techniques.
* Wikipedia:Citing sources/Further considerations – information of additional interest.
* Wikipedia:Citation templates – a full listing of various styles for citing all sorts of materials.
* Wikipedia:External links – for information about the External links appendix
* Wikipedia:Improving referencing efforts
* Wikipedia:Inline citation
* Wikipedia:Layout#Further reading – for information about the Further reading appendix
* Wikipedia:List of sources
* Wikipedia:Referencing for beginners – a simple practical guide to getting started.
* Wikipedia:Scientific citation guidelines – guidelines for dealing with scientific and mathematical articles.
Citation problems
* :Template:Citations missing – template to add where citations are needed
* Wikipedia:A suggested improvement 0001
* Wikipedia:Linkrot – guide to preventing link rot
* Wikipedia:Citation needed – explanation of citation needed template 
* Wikipedia:Copyright problems – in case of text that has been copied verbatim inappropriately.
* Wikipedia:WikiProject Citation cleanup – a group of people devoted to cleaning citations
* Wikipedia:Bombardment – an essay regarding the overuse of citations
* Wikipedia:Citation overkill – why too many citations on one fact can be a bad thing
Other
* Comparison of reference management software – side-by-side comparison of various Reference management software
==Notes==
==References==
* Concordia Libraries (Concordia University). Citation and Style Guides.
*Ritter, R. (2002). The Oxford Style Manual. Oxford University Press. ISBN 0198605641
*The Writers' Workshop, Center for Writing Studies. "Citation Styles Handbook: APA", University of Illinois. 
*The Writers' Workshop, Center for Writing Studies. "Citation Styles Handbook: MLA", University of Illinois. 
*University of Chicago Press. (2003). The Chicago Manual of Style, 15th edition. ISBN 0-226-10403-6
==Further reading==
* A writer's practical guide to MLA documentation
* AMA Citation Style
* Chicago/Turabian Documentation
* 
* Guide to Citation Style Guides
* Uniform Requirements for Manuscripts Submitted to Biomedical Journals
* American Chemical Society reference style guidelines
* Citation Machine
Category:Terminology