Citing the Dictionary and Other Online Sources

A citation of any online dictionary or thesaurus should include the following information:

  • headword of the entry cited (in quotes)
  • title of the source (in italics)
  • date the dictionary or thesaurus was published, posted, or revised (Use the copyright date noted at the bottom of this and every page of the Merriam-Webster Dictionary.)
  • full URL of the site (up to and including the file name)
  • date you accessed the dictionary (in parentheses)

Here are three ways you might cite the entry for hacker in the Merriam-Webster Online Dictionary, if you accessed it on May 8, 2011.

"hacker." 2011. (8 May 2011).

MLA Style:

"hacker." Merriam-Webster, 2011.

Web. 8 May 2011.

APA Style:

hacker. 2011. In

Retrieved May 8, 2011, from

Citing Other Online Sources

There is no universally accepted standard for citing online sources, but it is generally adequate to indicate the document's Web address, or URL (uniform resource locator), somewhere in the citation, usually following the date on which the electronic document was published, posted, or last revised (if known).

Thus a typical citation of an online source would show the author's name, the title of the document, the title of the complete work (such as the name of a periodical) in italics, the date, and the full URL. A URL is composed of the protocol used (such as http for Web pages; other less common protocols include gopher, ftp, and telnet), the server's identification, the directory path, and the file's name.

Here are a five sample citations of online sources:

Agmon, Eytan. "Beethoven's Op. 81a and the Psychology of Loss." Music Theory Online 2, 4 (1996). issues/mto.96.2.4/mto.2.4.agmon.html

Davies, Al. 1997. Mitral Valvular Prolapse Syndrome. Medical Reporter 2, 11 (Feb.).

Thursby, Ray. "Hopping into hybrids." Aug. 2000.

In many cases it is necessary or desirable to include the date of access as well. Note that the date of access will often be the only date shown, since many online documents do not include dates.

Walker, John. "Resources for Learning French." (12 Aug. 2007).

Periodicals published on paper that happen to be accessed online may be cited just like normal periodicals, with no acknowledgment of their online status, if it is clear that the text has not been altered for the online version.

References to mailing lists or newsgroup postings should begin with the author's name, include the subject line (or a made-up descriptive subject line), and provide the name and electronic address of the mailing-list server or newsgroup and the date posted. A personal e-mail message can be called "Personal communication" with no mention of its electronic medium.

Marchand, Jim. "L'humour de Berceo." (1 Oct. 1997).
Medieval Texts Discussion List.

Massey, Neil. "Year 2000 and Sendmail 8.86." (1 Oct. 1997). comp.mail.sendmail

Many mailing-list discussions are archived after messages are posted. Archives are usually maintained on the mailing list's server and may also be available through a Web page. An archived message is cited in its original form unless the message was accessed through a Web server rather than the list server or newsgroup.

McCarty, Willard. "The Fate of Universities." 13 June 1997. Humanist Discussion Group. Humanist/v11/0097.html

Note: Since many online sources are highly subject to change or deletion, any online text likely to be cited — including personal e-mail messages — should always be either downloaded onto a disk or printed out and stored on paper (with a notation of the date accessed) as a permanent record.