Citing sources in APA style

APA style is a standard for formatting citations that is overseen by the American Psychological Association and is used by a number of disciplines. Any part of your paper that refers to ideas that are not your own – i.e., references from other books, articles, or websites – must be cited with both an in-text citation in the body of your paper, and a corresponding reference entry in the References page at the end of your paper.

In-text citations

In-text citations should include the last name of the author(s) and the year of the publication. In-text citations have two formats: parenthetical and narrative.

  1. Parenthetical: the author name and publication date appear in parentheses directly after the information or text. For example:
    1. Falsely balanced news coverage can distort the public’s perception of expert consensus on an issue (Koehler, 2016).
  2. Narrative: the author name and publication date are incorporated into the text as part of the sentence. The publication date remains in parentheses. For example:
    1. Koehler (2016) noted the dangers of falsely balanced news coverage.

References list

The references list provides a reliable way for readers to locate the works you are citing and to acknowledge previous scholarship. Citation formats will differ depending on the type of resource. Below are two common examples: a book with one author and a journal article with two authors.

  • Book: Author Last Name, First Initial. Middle Initial. (Copyright Year). Title of book. Publisher. DOI or URL (if applicable)
  • Article: Author Last Name, First Initial. Middle Initial., & Author, B. B. (Year). Title of article. Title of Periodical, Volume(Issue), #-#. URL

Keep these tips in mind when compiling your references list:

  • Start the references list on a new page after the text and before any tables, figures, etc.
  • Alphabetize and double-space all reference list entries.
  • Use hanging indents (i.e., all lines except the first of each citation should be indented).
  • APA references are written in “sentence case.” You only need to capitalize the first letter of a title or subtitle. For a book called “The Extravagant Universe: Exploding Stars, Dark Energy, and the Accelerating Cosmos,” your citation should list the title as “The extravagant universe: Exploding stars, dark energy, and the accelerating cosmos.”

More information

To see more examples and other situations of citing sources in APA style, see the library's online APA Citation guide. You can also find the Publication Manual of the American Psychological Association (7th edition) in the Knowledge Center’s reference collection and the Book Stacks. Purdue’s Online Writing Lab has a comprehensive guide to APA style.