Wikipedia:CITE
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- 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 Wikipedia:CIT.
 | This page documents an English Wikipedia style guideline. It is a generally accepted standard that editors should attempt to follow, though it is best treated with common sense, and occasional exceptions may apply. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page. |
 | This page in a nutshell: This guideline discusses how to format and present Citations. The policy on sourcing is Wikipedia:Verifiability, which requires inline citations for any material challenged or likely to be challenged, and for all quotations. |
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.
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.[1]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==
OR ==Notes==
{{Reflist}}
- Immediately after the material in the text that requires citation, add:
- When the page is previewed or saved, the footnote number will automatically appear in the position of the .. 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
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
- Example: "This is a quotation."[1]
- Example: Bertrand Russell explained the Fallacy as follows:[2]
- Example: Martin Davis has described some of Burgin's claims as "misleading".[2]
When writing about living persons
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 a claim is doubtful but not harmful, use the {{fact}} 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: Source: Downloaded from http://news.bbc.co.uk/1/hi/world/europe/4280841.stm
- If you got the image from an offline source, you should specify:
- Example: Source: Scanned from public record #5253 on file with Anytown, Somestate public surveyor
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.[3]
- Shortened footnote: By placing the citation in the list and naming only the author, year, and page number in a footnote.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.
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.[4] 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.[5]
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.
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:Footnote system
For a citation to appear in a footnote, it needs to be enclosed in "ref" tags. You can add these by typing at the front of the citation and at the end. Alternatively you may notice below the edit box there is a list of "markup" which includes – 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 details of the citation. Thereafter, the same footnote may be used multiple times by adding . 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 The example below shows what this would look like in the edit box: Below is how this would look in the article, once you had previewed or saved your edited section: Where the issues are not contentious, you can combine references to avoid clutter: 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 adding "shortened notes" citations to an article: Below is how this would look once the edit has been saved: Shortened notes using titles rather than publication dates could look like this in the article: 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. 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: Below is how this would look once the edit has been saved: 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: which appears as: 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. Full citations for books typically include: 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. 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. For example: The quick brown fox jumps over the lazy dog.[7] Amazingly few discotheques provide jukeboxes.[8] How razorback-jumping frogs can level six piqued gymnasts.[9] ===References=== Defined references must be used within the body; unused references will show an error message. Dead links should be repaired or replaced if possible. In most cases one of the following approaches will give an acceptable alternative. 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==
The Sun is pretty big,[1] but the Moon is not so big.[2] The Sun is also quite hot.[3]
Notes
The Sun is pretty big, but the Moon is not so big. The Sun is also quite hot.[1]
Notes
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 {{sfn}} or {{harvnb}} templates. 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. The Sun is pretty big,[1] but the Moon is not so big.[2] The Sun is also quite hot.[3]
Notes
References
Notes
Parenthetical reference
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. 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
Embedded links
*Plunkett, John. [http://media.guardian.co.uk/site/story/0,14173,1601858,00.html "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. Non-English sources
Convenience links
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
Citation styles
Full citations for journal articles typically include:
Citations for newspaper articles typically include:
Citations for World Wide Web articles typically include: 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:
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: Retrieved 2008-07-15.Carr A, Ory D (2006). [http://dx.doi.org/10.1371/journal.pmed.0030496 Does HIV cause cardiovascular disease?] ''PLoS Medicine'', 3(11):e496.Citation templates and tools
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. List-defined references
|refs=. These reduce citation-template clutter within articles. As with other citation templates, 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 quick brown fox jumps over the lazy dog.<ref name="refname1" group="Ref"/>
Amazingly few discotheques provide jukeboxes.<ref name="refname2" group="Ref"/>
How razorback-jumping frogs can level six piqued gymnasts.<ref name="refname3" group="Ref"/>
===References===
{{reflist|group="Ref"|refs=
<ref name="refname1">This is reference 1.</ref>
<ref name="refname2">This is reference 2.</ref>
<ref name="refname3">This is reference 3.</ref>
}}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
Programming tools
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:
to the end of Special:MyPage/monobook.js. Then, save the page and bypass your browser's cache.
importScript("User:Smith609/endnote.js");
Preventing and repairing dead links
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
Citation problems
Other Notes
References
Further reading
