What Is a Citation?

A citation is a reference to the source of information used in your research. Any time you directly quote or paraphrase the essential elements of someone else’s idea in your work, a citation should follow.  Direct quotations should be surrounded by quotations marks and are generally used when the idea you want to capture is best expressed by the source.   Paraphrasing involves rewording an essential idea from someone else’s work, usually to either condense the point or to make it better fit your writing style.

Common knowledge does not need to be followed by a citation.  Common knowledge means something that most people would already know, such as “George Washington was the first president of the United States.”  You can read about how to determine whether something is considered common knowledge here.

Citations include identifying information about the source you used. For an article, that includes:

  • author(s)
  • article title
  • publication information (journal title, date, volume, issue, pages, etc.)
  • for an online resource, the permalink/PURL/stable URL

There are many kinds of sources you might use besides articles, but we’ll talk more about that later.

When you search the library’s databases for articles or e-books, the list of results you see is actually a list of citations.  Writing down the citation information when you find it will make it easier to locate the same source again when you need it, either to include at the end of your paper or for future research on that topic.

Database results list

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At the end of a research paper or article, citations will be listed in the form of a works cited page (MLA), reference list (APA) or bibliography. There are also stand-alone bibliographies.  This is where all of the identifying information about a source is assembled, ordered and formatted.

Example of a list of citations. A Works Cited page.

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Example of a list of citations. A References page.

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Example of a list of citations. A Bibliography.

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Citations also appear inside research papers and articles as in-text documentation.  In-text documentation usually includes brief information about a source, such as the author and page number, to allow the reader to match it up with the full information about the source at the end of the paper.  In-text documentation may appear in the form of:

  • parenthetical notes at the end of the sentence or paragraph
  • Example of a parenthetical in-text citation.

    Please click the image to see a full-sized version.

  • endnotes, usually indicated with a superscript numeral near the idea you are referencing followed by a detailed note at the end of the paper

    Example of an endnote. A numeral to identify the citation is placed in superscript at the end of the quoted or paraphrased material. At the end of the document, the citations are listed in the order that they appeared in the document.

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  • footnotes, usually indicated with a superscript numeral near the idea you are referencing followed by a detailed note at the bottom of the page

    Example of a footnote. After the paraphrased or quoted text, there is a superscript numeral to identify the citation. At the end of the page, all the citations for that page are listed.

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A citation contains different pieces of identifying information about your source depending on what type of source it is.  In academic research, your sources will most commonly be articles from scholarly publications, but there are many types of sources you might use, including books, book chapters, films, song lyrics, musical scores, interviews, e-mails, blog entries, art works, lectures, web sites and more. You can view lists of some commonly used source types here.