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APA Style Guide

The American Psychological Association (APA) documentation style is widely used for writing in the social sciences.

The current 7th edition of the Publication Manual of the American Psychological Association is available in print at the Biddeford and Portland Libraries.

The APA Style Website also offers guidance and citation examples and the full manual available for purchase.


When paraphrasing or quoting an author directly, you must credit the source with an in-text citation. Cited references are then listed alphabetically by author’s last name in a “References” section at the end of your paper.

In the references section, list all author names up to and including 20 authors; For 21 authors or more, include the first 19 followed by three dots (…) then the name of the last author.

Use hanging indentation to format references.

DOIs and URLs

References to online sources such as journals and e-books contain the same elements in the same order as do references to print sources, with the addition of a Digital Object Identifier (DOI) or URL so that the reader can locate the source.

  • You only need a retrieval date if the content you are citing is likely to change, such as a journal articles in pre-publication or undated content from websites
  • Use a DOI instead of a URL if available
  • If no date is given for a resource, add n.d. for no date
  • Hyperlink URLs when a paper is intended to be read online

In-Text Citations

The in-text citation is a brief reference within your text that indicates the source you consulted. It should properly attribute any ideas, paraphrases, or direct quotations to your source and should direct readers to an entry in the reference list.


Include an in-text citation whenever you paraphrase or summarize the ideas of another author. An in-text citation consists of the author’s name and publication year in parentheses at the end of the sentence containing the summary.

Example: (Winkleman, 2020).

Authors Name in the sentence

Use just the publication year in parentheses if you name the author in the sentence.

Example: “As a leading expert in the subject, Winkleman (2020) asserts that…”

Multiple Authors

For two authors, separate using an ampersand (&). If you are using the author’s names in the sentence, use the word “and.”

Example: (Winkleman & Clark, 2019) or According to Winkleman and Clark (2019)…

For three or more authors, list only the first author’s name followed by “et al.” in every citation, even the first, unless doing so would create ambiguity between different sources.

Example: (Winkleman et al., 2019) or Winkleman et al. (2019) suggest…

Direct Quote

Add the page number when using a direct quote.

Example: (Winkleman, 2009, p. 134).

Reference Examples

Include a period after each reference element, except after a URL or DOI because it may interfere with the link. Use a comma between parts of the same reference element, such as an article or chapter title, or between authors names.

Separate journal volume and issue numbers using parentheses.

Italicize the titles of books and journals. Capitalize the titles of journals. Books, chapters and article titles use sentence case.


Article from a Print Journal OR a Research Database

Rowe, J. R. (2009). Nuclear power in a carbon-constrained world. Daedalus, 138(4), 81-92.

Online Journal Article

Brown, J. D., Sintzel, J., St. Arnault, D., & George, N. (2009). Confidence to foster across cultures: Caregiver perspectives. Journal of Child and Family Studies, 18(6), 633 -642. https://doi:10.1007/s10826-009-9264-z

Note: Use a DOI if available, otherwise use the URL of the article source.

Newspaper Article

Dvorak, P. (2009, May 30). On the street and on Facebook: The homeless stay wired — Mr. Pitts lacks a mailing address but he’s got a computer and a web forum. Wall Street Journal, p. A-1.

NOTE: If the article is from an online newspaper, include the article URL instead of the page number.


Note: Use the same formats for both print books and e-books.

Single Author

Winkleman, M. (2009). Culture and health: Applying medical anthropology. Jossey-Bass.

Two to 20 authors

Robnett, R. H., & Chop, W. C. (2010). Gerontology for the health care professional. Jones and Bartlett Publishers.

Note: For 21 authors or more, include the first 19 followed by three dots(…), then the name of the last author.

Chapter in an Edited Book

Hart, L. A. (2006). Community context and psychosocial benefits of animal companionship. In A. H. Fine (Ed.), Handbook on animal assisted therapy (pp. 73- 94). Elsevier.

Note: add either the publisher or the URL at the end. This example also demonstrates an editor and an edition of the book. Do not add these elements if not present.

Web Page

Arthritis Foundation. (2012). Exercise and arthritis.

Note: If you cannot locate a publication date, use (n.d.). Include a retrieval date if the page’s contents are likely to change over time, such as a publicly edited wiki.


Film or Television

American Psychological Association. (Producer). (2008). Assessing alcohol problems using motivational interviewing [Film; educational DVD]. 

Note: Add the writer, directors, host, producers, composer or artist as the author. 

YouTube Video

Cain, S. (2012). The Power of introverts [Video]. TED Conferences.


Hacking, C. (2018). CT head coronal – labeling questions [image]. Radiopaedia. 

Blog Post

Doctorow, C. (2019, September 24). At the UN, Greta Thunberg excoriates world leaders and her elders for climate inaction. Boing Boing.


Rooks, J. (Host). (2019, November 6). Conserving Maine’s islands: What’s  being done to protect Maine islands from climate change & threats [Audio podcast episode]. In Maine Calling. Maine Public.


Published Dissertation

Demeo, A. E. (2013). A three pronged approach to community scale renewable energy: Education, incremental capital investment and smart grid technology (Publication No. 3575461). [Doctoral dissertation, The University of Maine].

Note: If the dissertation is from a research database, use the database name instead of a URL.

Unpublished Dissertation

Smith, M. E. (2020) Ethical leadership in higher education: Perceptions and practices at a private university. [Unpublished doctoral dissertation]. University of New England.

Legal Case

Despres v. Moyer, 827 A. 2d 61 (S.C. ME 2003).

NOTE: For information on preparing legal references, the APA refers writers to the latest edition of The Bluebook: A Uniform System of Citation.

Questions & Help

If you have questions on this, or another, topic, contact a librarian for help!