APA Citation

APA Style (short for American Psychological Association Style) is a way of formatting papers and citing sources in several disciplines, including most of the sciences, health fields and communications.

Several websites can provide excellent resources and help with your APA paper, including the following:


The official APA Style website, from the American Psychological Association, that provides a lot of great, specific answers to common questions about this style.


Liking APA Style on Facebook will help you educate yourself about APA over time. They often post links to their blog, which includes many helpful answers and tips about this great formatting style.


Our own Val A. Browning Library has provided a great citation guide for APA Style on their website.


Of course, Purdue University’s amazing online writing lab website holds many writing treasures in its countless pages. Among these is an amazingly comprehensive, yet simple, guide to APA Style.

Along with these resources, here are some tips the Writing Center tutors have compiled themselves to aid students in the writing process:

In-Text Citations

Capitalization, Quotes, and Italics/Underlining

  • If you refer to the title of a source within your paper, capitalize all words that are four letters long or greater within the title of a source: Permanence and Change. Exceptions apply to short words that are verbs, nouns, pronouns, adjectives, and adverbs: Writing New Media, There is Nothing Left to Lose.
  • When capitalizing titles, capitalize both words in a hyphenated compound word: Natural-Born Cyborgs.
  • Capitalize the first word after a dash or colon: “Defining Film Rhetoric: The Case of Hitchcock’s Vertigo.”
  • Italicize or underline the titles of longer works such as books, edited collections, movies, television series, documentaries, or albums: The Closing of the American Mind; The Wizard of Oz; Friends.
  • Put quotation marks around the titles of shorter works such as journal articles, articles from edited collections, television series episodes, and song titles: “Multimedia Narration: Constructing Possible Worlds”; “The One Where Chandler Can’t Cry.”

Short Quotations

If you are directly quoting from a work, you will need to include the author, year of publication, and the page number for the reference (preceded by “p.”). Introduce the quotation with a signal phrase that includes the author’s last name followed by the date of publication in parentheses.

According to Jones (1998), “Students often had difficulty using APA style, especially when it was their first time” (p. 199).

Jones (1998) found “students often had difficulty using APA style” (p. 199); what implications does this have for teachers?

If the author is not named in a signal phrase, place the author’s last name, the year of publication, and the page number in parentheses after the quotation.

She stated, “Students often had difficulty using APA style,” (Jones, 1998, p. 199), but she did not offer an explanation as to why.

Long Quotations

Place direct quotations longer than 40 words in a free-standing block of typewritten lines, and omit quotation marks. Start the quotation on a new line, indented five spaces from the left margin. Type the entire quotation on the new margin, and indent the first line of any subsequent paragraph within the quotation five spaces from the new margin. Maintain double-spacing throughout. The parenthetical citation should come after closing punctuation mark.

Jones’s (1998) study found the following:

Students often had difficulty using APA style, especially when it was

their first time citing sources. This difficulty could be attributed to

the fact that many students failed to purchase a style manual or to ask

their teacher for help. (p. 199)


If you are paraphrasing an idea from another work, you only have to make reference to the author and year of publication in your in-text reference, but APA guidelines encourage you to also provide the page number (although it is not required).

According to Jones (1998), APA style is a difficult citation format for first-time learners.

APA style is a difficult citation format for first-time learners (Jones, 1998, p. 199).


APA style has a series of important rules on using author names as part of the author-date system. Print and electronic documents are cited in the same way using the author-date style, however, there are additional rules for citing indirect sources, certain electronic sources, and sources without page numbers.

A Work by Two Authors: Name both authors in the signal phrase or in the parentheses each time you cite the work.

Use the word “and” between the authors’ names within the text…

Research by Wegener and Petty (1994) showed…

…and use (&) in the parenthetical reference following the sentence.

(Wegener & Petty, 1994)

A Work by Three to Five Authors: List all the authors in the signal phrase or in parentheses the first time you cite the source.

(Kernis, Cornell, Sun, Berry, & Harlow, 1993)

In subsequent citations, only use the first author’s last name followed by “et al.” in the signal phrase or in parenthetical reference following the sentence.

(Kernis et al., 1993)

Six or More Authors: Use the first author’s name followed by et al. in the signal phrase…

Harris et al. (2001) argued…

…or in parenthetical reference following the sentence.

(Harris et al., 2001)

Unknown Author: If the work does not have an author, cite the source by its title in the signal phrase or use the first word or two in the parentheses. Titles of books and reports are italicized or underlined; titles of articles and chapters are in quotation marks.

A similar study was done of students learning to format research papers (“Using APA,” 2001).

Note: In the rare case the “Anonymous” is used for the author, treat it as the author’s name (Anonymous, 2001). On your Reference list, use the name Anonymous as the author.

Organization as an Author: If the author is an organization or a government agency, mention the organization in the signal phrase or in the parenthetical citation the first time you cite the source.

According to the American Psychological Association (2000),…

If the organization has a well-known abbreviation, include the abbreviation in brackets the first time the source is cited and then use only the abbreviation in later citations.

First citation: (Mothers Against Drunk Driving [MADD], 2000)

Second citation: (MADD, 2000)

Two or More Works in the Same Parentheses: When your parenthetical citation includes two or more works, order them the same way they appear on your Reference list, separated by a semi-colon.

(Berndt, 2002; Harlow, 1983)

Authors with the Same Last Name: To prevent confusion, use first initials with the last names.

(E. Johnson, 2001; L. Johnson, 1998)

Two or More Works by the Same Author in the Same Year: If you have two sources by the same author in the same year, use lower-case letters (a, b, c) with the year to order the entries on the Reference list. Use the lower-case letters with the year in the in-text citation.

Research by Berndt (1981a) illustrated that…

Personal Communication: For interviews, letters, e-mails, and other person-to-person communication, cite the communicator’s name, the fact that it was personal communication, and the date of the communication. Do not include personal communication on the Reference list.

A. P. Smith also claimed that many of her students had difficulties with APA style (personal communication, November 3, 2002).

(E. Robbins, personal communication, January 4, 2001).

Indirect Sources: If you use a source that was cited in another source, name the original source in your signal phrase. List the secondary source on your Reference list and include the secondary source in the parentheses.

Johnson argued that… (as cited in Smith, 2003, p. 102).

Note: When citing material in parentheses, set off the citation with a comma, as above.


Electronic Sources

If possible, cite an electronic document the same as any other document by using the author-date style.

Kenneth (2000) explained…

Unknown Author and Unknown Date: If no author or date is given, use the title in your signal phrase or the first word or two of the title in the parentheses and use the abbreviation “n.d.” (for “no date”).

Another study of students and research decisions discovered that students succeeded with tutoring (“Tutoring and APA,” n.d.).

Electronic Books

Electronic books may include books found on personal websites, databases, or even in audio form.

  • Use the following format if the book you are using is only provided in a digital format or is difficult to find in print.
  • If the work is not directly available online or must be purchased, use “Available from,” rather than “Retrieved from,” and point readers to where they can find it.
  • For books available in print form and electronic form, include the publish date in parentheses after the author’s name.
  • For references to e-book editions, be sure to include the type and version of e-book you are references (e.g., “[Kindle DX version]”).
  • If DOIs are available, provide them at the end of the reference.
    • A digital object identifier (DOI) is a unique alphanumeric string assigned by a registration agency (the International DOI Foundation) to identify content and provide a persistent link to its location on the Internet.
    • The publisher assigns a DOI when your article is published and made available electronically.
    • All DOI numbers begin with a 10 and contain a prefix and a suffix separated by a slash. The prefix is a unique number of four or more digits assigned to organizations; the suffix is assigned by the publisher and was designed to be flexible with publisher identification standards.
    • When DOIs are available, you should include them for both print and electronic sources.
    • The DOI is typically located on the first page of the electronic journal article, near the copyright notice. The DOI can also be found on the database landing page for the article.

Sources without Page Numbers

When an electronic source lacks page numbers, you should try to include information that will help readers find the passage being cited.

  • When an electronic document has numbered paragraphs, use the symbol, or the abbreviation “para.” followed by the paragraph number (Hall, 2001, ¶ 5) or (Hall, 2001, para. 5).
  • If the paragraphs are not numbered and the document includes headings, provide the appropriate heading and specify the paragraph under that heading. Note that in some electronic sources, like Web pages, people can use the Find function in their browser to locate any passages you cite.

According to Smith (1997), … (Mind over Matter section, para. 6).

Note: Never use the page numbers of Web pages you print out; different computers print Web pages with different pagination.


If you only cite an abstract but the full text of the article is also available, cite the online abstract as any other online citations, adding “[Abstract]” after the article or source name. However, if the full text is not available, you may use an abstract that is available through an abstracts database as a secondary source.

Paterson, P. (2008). How well do young offenders with Asperger Syndrome cope in custody?: Two        prison case studies [Abstract]. British Journal of Learning Disabilities, 36(1), 54-58.

Hendricks, J., Applebaum, R., & Kunkel, S. (2010). A world apart? Briding the gap between theory        and applied social gerontology. Gerontologist, 50(3), 284-293. Abstract retrieved from        Abstracts in Social Gerontology databast. (Accession No. 50360869)

APA Reference List: Basic Rules

Your Reference list should appear at the end of your paper. It provides the information necessary for a reader to locate and retrieve any source you cite in the body of the paper. Each source you cite in the paper must appear on your Reference list; likewise, each entry on the Reference list must be cited in your text.

Your references should begin on a new page separate from the text of the essay; label this page References (with no quotation marks, underlining, etc.), centered at the top of the page. It should be double-spaced just like the rest of your essay.

Basic Rules

  • All lines after the first line of each entry on your Reference list should be indented one-half inch from the left margin. This is called hanging indentation.
  • Authors’ names are inverted (last name first); give the last name and initials for all authors of a particular work unless the work has more than six authors. If the work has more than six authors, list the first six authors and then use et al. after the sixth author’s name to indicate the rest of the authors.
  • Reference list entries should be alphabetized by the last name of the first author of each work.
  • If you have more than one article by the same author, single-author references or multiple-author references with the exact same authors in the exact same order are listed in order by the year of publication, starting with the earliest.
  • When referring to any work that is NOT a journal, such as a book, article, or Web page, capitalize only the first letter of the first word of a title and subtitle, the first word after a colon or a dash in the title, and proper nouns. Do not capitalize the first letter of the second word in a hyphenated compound word: Writing new media.
  • CAPITALIZE all major words in journal titles.
  • Italicize titles of longer works such as books and journals.
  • Do not italicize, underline, or put quotes around the titles of shorter works such as journal articles or essays in edited collections.


Print Articles

General Format

Author’s Last Name, First Initials. (Date of publication). Article title. Name of Periodical, volume number, pages.


[journal article — volume 166. Note how multiple authors are shown]

Agusti, A.G., Sauleda, J., Miralles, C.,Togores, B., Sala, E., & Batle, S. et al. (2002, August 15). Skeletal Muscle Apoptosis and Weight Loss In Chronic Obstructive Pulmonary Disease. American Journal of Respiratory and Critical Care Medicine, 166, 485-489.

[encyclopedia article – note Bhutto, Benazir is the title of the article, not the author’s name] Bhutto, Benazir. (1997). In Encyclopedia Americana. (Vol.3), 644-45. Danbury, CT: Grolier, Inc.

[popular magazine article -- no author's name given]

The Legacy: A Round Table of Historians Ponders How the Future Will View September 11. (2002, Sept. 9). Newsweek, 62-65.

Books and Book Chapters

General Format

Author’s Last Name, First Initials. (publication year). Title: Capitalize the first  word only of title and subtitle (edition or volume number, if any). Place of Publication: Publisher’s Name.


[book chapter]
Pendleton, D. A. (2000). The Government Should Legislate Morality. Opposing Viewpoints: American Values, 190-195. 

[book with multiple authors]

Hawking, S. W., Thorne, K. S., Novikov, I., Ferris, T., & Lightman, A. (2002). The future of spacetime. New York: W.W. Norton & Co.

[book with an editor instead of an author]

Lowenherz, D. H., Ed. (2002). The 50 greatest love letters of all time. New York:  Crown.

[book with a subtitle]

Needleman, J. (2002). The American soul: Rediscovering the wisdom of the founders. New York: Putnam.

Online Sources

[library database with DOI]

Chaffe-Stengel, P., & Stengel, D. (2012). Working with sample data: Exploration and inference. http://dx.doi.org/10.4128/9781606492147


Conoloff, A. (2012). Salvaging the suburbs. doi:11.8870/6001/2122.442.261

[book chapter from a library database]*

Quina, K., & Kanarian, M. A. (1988). Continuing education. In P. Bronstein & K. Quina (Eds.), Teaching a psychology of people: Resources for gender and sociocultural awareness (pp. 200-208). Retrieved from http://www.apa.org/

*If the chapter has a DOI, include it following the “Library database with DOI” example above. If not, do a Web search for the homepage of the publisher of the book and use the homepage URL after the words “Retrieved from”.


Seton, E. T. (1911). The Arctic prairies: A canoe-journey of 2,000 miles in search of the caribou. Retrieved from http://www.gutenberg.org/etext/6818

U.S. Government Accountability Office. (2010, March). Information security: Concerted effort needed to consolidate and secure Internet connections at federal agencies (Publication No. GAO-10-237). Retrieved from http://www.gao.gov/assets/310/301876.pdf