Wikipedia:Citing sources

One of the Wikipedia policies and guidelines.

Cite sources: provide references that help the reader to check the veracity of the article and to find more information.

If you consult an external source while writing an article, citing it is basic intellectual honesty. More than that, you should actively search for authoritative references to cite. If you are writing from your own knowledge, then you should know enough to identify good references that the reader can consult on the subject—you won't be around forever to answer questions. (Also, this forces you to check your facts, and you might find that you don't know everything.) The main point is to help the reader—cite whatever you think will be most helpful.

This applies when writing about opinions, as well—beware the temptation to write, "Some people say..." Who said it, and where and when?

Adding references, especially for information not already backed by citations, is also a good way to enhance even articles you didn't write.

References should be collected at the end of the article; see below for a proposed style. The most important thing is to enter the complete reference information, however; details like formatting can be dealt with later if necessary.

Proposed Citation Style

There is currently no consistent Wikipedia citation style, and citations are very poor at the moment. For a list of common citation styles, see e.g.: Citation Style Guides

Proposal: Wikipedia should use a style based on the APA guidelines (see above link)

In the text of an article, cite references parenthetically as "(Author-Last-Name, Year)". If necessary, add chapters ("chap. 3") or pages ("p. 15" or "pp. 12–23") after the year (+ comma), e.g. if the information is hard to find in a large book. When a reference is used as a noun, put the year in parentheses, e.g. "Milton (1653) says..." For two authors, use (Author1 & Author2, year); for more authors, use (Author1 et al., Year). Note that such in-text citations are often unnecessary, unless there is a long list of references and it is not clear which one the reader should consult for more information on a specific topic.

At the end of an article, under a ==References== heading, list the references as a bulleted (*) list in alphabetical order by author (and by year for identical authors), in one of the following example styles:

Books

Lincoln, Abraham; Grant, U. S.; & Davis, Jefferson (1861). Resolving family differences peacefully (3rd ed.). Gettysburg: Printing Press. ISBN 0-12-345678-9.

For an edited book, put "(Ed.)" or "(Eds.)" in parentheses after the last author, before the date. The ISBN (which is wikified automatically) is optional. For a specific article or chapter in an edited book, use:

Pooh, W. T. & Robin, C. (1926). How to catch a heffalump. In A. A. Milne (Ed.), The Karma of Kanga, pp. 23–47. Hundred Acre Wood: Wol Press.

Wikipedia has no shortage of space, so you need not abbreviate names; a good guideline is to list them as they are written in the original article/book.

If Wikipedia has a page for the book, make the book title a link to it, but retain the full reference (e.g. for printing).

Journal articles

Brandybuck, M. (1955). Herb-lore of the Shire. J. Royal Institute of Chemistry 10 (2), 234–351.

Note that the numbers after the journal title indicate: volume (issue number, optional), page numbers. Do not capitalize every word of the article title, only the first word, proper names, and the first word after a colon/period/dash. For an article that is available online, make the article title a link to the online version.

Newspaper/magazine articles (or online periodicals)

Blair, Eric Arthur (Aug. 29, 1949). Looking forward to a bright tomorrow. New English Weekly, p. 57.

Or, for articles without a named author, put the title first:

On the importance of modesty (May 5, 1821). Pravda, pp. B1, C12.

Again, for online articles, make the article title a link to the URL; it may not be possible to supply a page number in this case, e.g.:

Chalmers, Rachel (Sep. 1, 2000). Guru of the Unix gurus. Salon.

Web sites (not from periodicals)

Gates, B. & Ballmer, S. (1998). The Big Open-source Advocacy Homepage. Retrieved Aug. 5, 2003 from http://www.opensource.org/halloween/halloween1.php.

In this case, we list the URL separately so that the reference is still useful if the article is printed. The parenthesized date should be the date/year the document was created, or last edited; this should be omitted if it cannot be determined.

Notes

Example APA styles for many other document types can be found at the "Citation Style Guides" page above. Ultimately, though, use your common sense — what information does the reader need in order to find the reference in question?

Page ranges should use an "n" dash (–, –), not a hyphen (-).

It is also useful to link author names to their Wikipedia page (if any), assuming that they haven't already been linked to in the article text, to give background information on sources and other works they may have written.

Citing Wikipedia

For suggestions on how to cite Wikipedia, see Wikipedia:Citing Wikipedia