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APA conventions

To see the most updated information about APA conventions, please visit www.apastyle.apa.org.

APA style requires two elements for citing outside sources: parenthetical (in-text) references, and a references list. Together, these elements allow your reader access to the sources you consulted.
For the system to function, all authors cited in the text must appear in the references list, and all authors listed must have been cited in the text.

Parenthetical (in-text) references
Introduction to parenthetical citations
This section provides guidelines on how to use parenthetical citations to cite original sources in the text of your paper. These guidelines will help you learn the essential information needed in parenthetical citations, and teach you how to format them correctly.
Parenthetical citations are citations to original sources that appear in the text of your paper. This allows the reader to see immediately where your information comes from, and it saves you the trouble of having to make footnotes or endnotes.
The APA style calls for three kinds of information to be included in in-text citations. The author's last name and the work's date of publication must always appear, and these items must match exactly the corresponding entry in the references list. The third kind of information, the page number, appears only in a citation to a direct quotation.

Where to place parenthetical citations
You have three options for placing citations in relation to your text:

Option Description Sample Citation
Idea-focused Place the author(s) and date(s) in parentheses at an appropriate place in or at the end of a sentence Researchers have pointed out that the lack of trained staff is a common barrier to providing adequate health education (Fisher, 1999) and services (Weist & Christodulu, 2000).
Researcher-focused Place only the date in parentheses Fisher (1999) recommended that health education be required for high school graduation in California.
Chronology-focused Integrate both the author and date into your sentence In 2001, Weist proposed using the Child and Adolescent Planning Schema to analyze and develop community mental health programs for young people.

Additional Guidelines

  • Place citations in sentences and paragraphs so that it is clear which material has come from which sources.
  • Use pronouns and transitions to help you indicate whether several sentences contain material from the same source or from different sources.

Symthe (1990) found that positioning influences ventilation. In his study of 20 ICU patients, he used two methods to... . However, his findings did not support the work of Karcher (1987) and Atley (1989) who used much larger samples to demonstrate that ...

Cite source with one or two authors
The following table gives some examples of how to cite sources with one or two authors.

When you have...

Here's what you do Sample citation
First and subsequent citations Within a paragraph, omit the year in citations after the first one if no confusion with other studies will result

Fisher (1999) administered a questionnaire ... Fisher's results indicated ...
[new paragraph] The questionnaire administered by Fisher (1999) was used by ...

A source with 1 or 2 authors Cite name(s) in first and all subsequent citations

(Adkins& Singh, 2001)
Adkins and Singh (2001)

Authors with same surname Use initials even if the years are different D. Baldwin (2001) and M. L. Baldwin (1999)

Cite source with three or more authors
The following table gives some examples of how to cite sources with three or more authors.

When you have... Here's what you do Sample citation
A source with three to five authors In all citations after the first, use the first author's name followed by et al. First citation: (Baldwin, Bevan,& Beshalke, 2000)

Subsequent citation: (Baldwin et al., 2000)
A source with six or more authors Use the first author's name followed by et al. in all citations

6 authors: (Utley et al., 2001)

7 authors: (Yawn et al., 2001)

[Note: In the reference list, use of et al. begins with 7-author references.]

Sources with two or more six-author groups with same first surname If two or more six-author groups shorten to the same surname, cite the surnames of as many subsequent authors as needed to distinguish references. (Baldwin, Utley et al., 2001)

(Baldwin, Bevan et al., 2000)

Cite source with no author
The following table gives some examples of how to cite sources with no author.

When you have... Here's what you do Sample citation
A source with no author Use the first few words of the title - in quotation marks for article or chapter, in Italics for self-contained item ("Mad Cow," 2001)

(Sleep Medicine, 2001)
An edited work with no author Use editor(s) names in the author position See guidelines for citing authored works

Cite multiple sources in one reference
The following table gives some examples of how to cite multiple sources in one reference.

When you have... Here's what you do Sample citation
Two or more works in parentheses Arrange by order of the reference list; use a semicolon between works Several researchers (Greenberg, Domitrovich, & Bumbarger, 2000; Roy, 1995; Yawn et al., 2000)...
Representative works Use e.g. (for Sample citation) before parenthetical citations The need for more effective prevention of mental illness in children has been the focus of many reports (e.g. National Institute of Mental Health, 1998; U.S. Public Health Service, 2000; Weist, 2001).
Major work plus others Use see also after major work (Roy, 1995; see also Embar-Seddon, 2000; Greenberg, 2001)

Cite an electronic source
In general, you should cite an electronic source within your paper in the same way as you would a print source, by placing the author's last name (or short title of the source, if there is no author) and year of publication in parentheses.
The following table gives some examples of how to cite electronic sources in more unusual cases.

When you have... Here's what you do Sample citation
Entire Web site Don't put on reference list. Include URL in-text instead The University of Wisconsin's Writing Center Web site is an excellent source of information on writing (http://www.wisc.edu/writing/).
Direct quotation from electronic source without page numbers Use paragraph numbers (preceded by para. or ¶); add section numbers for long documents Universal interventions "target the general public or a whole population group that has not been identified on the basis of individual risk" (Greenberg et al., 2000, Section I, para. 20).

Additional information
Check the APA website (http://www.apastyle.org), where you will find links to the following:
- The information on electronic references from the 5th edition of the Publication Manual
- 'Tip of the Week' and archived tips
- Information on bias in language
- 'Ask the Expert' - an e-mail form that allows you to ask questions about APA style
- A form for requesting e-mail updates of APA style
- A chapter-by-chapter description of changes made in the 5th edition

Reference list entry: Book

Type of source

Sample entry in reference list

Book (1):
Basic form, single author
Baxter, C. (1997). Race equality in health care and education. Philadelphia: Ballière Tindall.
Book (2):
Editors in place of authors
Stock, G., & Campbell, J. (Eds.).(2000). Engineering the human genome: An exploration of the science and ethics of altering the genes we pass to our children. New York: Oxford University Press.
Book manuscript:
Submitted but not yet accepted; 3-6 authors
Walrath, C., Bruns, E., Anderson, K., Glass-Siegel, M. & Wiest, M. D. (2000). The nature of expanded school mental health services in Baltimore City. Manuscript submitted for publication.
Chapter in edited work:
Second or later edition
Roy, A. (1995). Psychiatric emergencies. In H. I. Kaplan & B. J. Sadock (Eds.), Comprehensive textbook of psychiatry. (6th ed., pp. 1739-1752). Baltimore: Williams & Wilkins.

Reference list entry: Dissertation

Type of source

Sample entry in reference list

Dissertation (1):
Abstracted in Dissertation Abstracts International (DAI); obtained from university
Fisher, C. J. (1999). The status of health education in California's public school districts: A comparison to state and national recommendations and status reports (Doctoral dissertation, University of Southern California, 1999). Dissertation Abstracts International, 61 (02), 1926.
Dissertation (2):
Abstracted in DAI; obtained from UMI
Embar-Seddon, A. R. (2000). Perceptions of violence in the emergency department.Disssertation Abstracts International, 61(02), 776A. (UMI No. 9963641)
Dissertation (3):
Retrieved from online database
Embar-Seddon, A. R. (2000). Perceptions of violence in the emergency department. [Abstract]. Dissertation Abstracts International, 61(02), 776A. Retrieved August 23,2001, from http://wwwlib.umi.com/dissertations/fullcit9963641

Reference list entry: Government report

Type of source

Sample entry in reference list

Government report (1):
From Government Printing Office (GPO); organization as author (group author)

National Institute of Mental Health. (1998). Priorities for prevention research (NIH Publication No. 98-4321). Washington, DC: U.S. Government Printing Office.
[Note: Any document available from GPO should show GPO as publisher.]

Government report (2):
Obtained online; organization as author (group author)
U.S. Public Health Service. (2000). Report of the surgeon general's conference on children's mental health: A national section agenda. Washington, DC: U.S. Department of Health and Human Services. Retrieved on August 25, 2001, from http://www.surgeongeneral.gov/chilreport.htm

Reference list entry: Journal article

Type of source

Sample entry in reference list

Journal article (1):
Basic form, single author
Roy, A. (1982). Suicide in chronic schizophrenia. British Journal of Psychiatry, 141, 171-177.
Journal article (2):
Journal paginated by issue, 3-6 authors
Baldwin, C. M., Bevan, C., & Beshalske, A. (2000). At-risk minority populations in a church-based clinic: Communicating basic needs. Journal of Multicultural Nursing & Health, 6(2), 26-28.
Journal article (3):
7 or more authors
Yawn, B. P., Algatt-Bergstrom, P. J., Yawn, R. A., Wollan, P., Greco, M., Gleason, M., et al. (2000). An in-school CD-ROM asthma education program. Journal of School Health, 70, 153-159.
Journal article (4):
In press
Smith, R. W., Huber, R. A., & Shotsberger, P. G. (in press). The impact of standards-guided equity and problem-solving institutes on participating science teachers and their students. North Carolina Journal of Teacher Education.
Journal article (5):
In Internet-only journal; secondary reference
Greenberg, M. T., Domitrovich, C., & Bumbarger, B. (2000, March 30). Prevention of mental disorders in school-aged children: Current state of the field. Prevention and Treatment, 4, Article 1. Retrieved August 24, 2001, from http://journals.apa.org/prevention/pre40001a.htm
Journal article (6):
Electronic version of print journal that differs from print version (e.g. no page numbers in text; tables reduced)
Wiest, M. D. (2001). Toward a public mental health promotion and intervention system for youth. Journal of School Health, 71, 101-104. Retrieved August 25, 2001, from ProQuest database.
Journal article (7):
Special issue of Internet journal based on print source

Hackett, E. J. (Ed.). (1994). Perspectives on scientific misconduct [Special issue, electronic version]. Journal of Higher Education, 65 (3)
[Note: Brackets are used to enclose information about the formof a document, 2 items in this case.]

Reference list entry: Magazine or newspaper article

Type of source

Sample entry in reference list

Magazine article:
Basic form

Greenberg, G. (2001, August 13). As good as dead: Is there really such a thing as brain death? New Yorker, 36-41.
[Note: Use vol. no. if available.]

Newspaper Article:
No author; electronic version found on searchable, aggregated database
Mad-cow may tighten blood-donor curbs. (2001, April 19). The Gazette [Montreal], p. A13. Retrieved August 25, 2001, from Lexis-Nexis database.

Reference list entry: Publication from a private organization

Type of source

Sample entry in reference list

Publication, private organization:
Basic form

Swift, A. C. (1985). Determining our children's future (Report no. 12). Milwaukee: Child Care of Wisconsin.

Reference list entry: Conference paper or poster session

Type of source Sample entry in reference list
Conference paper:
Basic form

Crespo, C. J. (1998 March). Update on national data on asthma. Paper presented at the meeting of the National Asthma Education and Prevention
Program, Leesburg, VA.

Poster session:
Form for non-online version would be the same except for retrieval statement

Binh, N. X., McCue, C., & O'Brien, K. (1999 October). English language and development work at Vinh University, Nghe An Province. Poster session presented at the Fourth International Conference on Language and Development, Hanoi, Vietnam. Retrieved August 23, 2001, from https://languages.ait.ac.th/

Reference list entry: Electronic source
IMPORTANT: for electronic source entries in your reference list, it's crucial to differentiate between electronic versions of print sources and electronic materials that are NOT duplicates of print sources.

Electronic versions of print sources


Electronic versions of print sources reproduce the exact same content, format, and page numbers as the print versions. For these kinds of electronic sources, you need to indicate that you read the source in the electronic version (by placing [Electronic version] after the title of the article), but you do NOT need to provide a retrieval date or a URL.


Knowles, E.S. (1999). Distance matters more than you think! An artifact clouds interpretation of Latane, Liu, Nowak, Bonevento, and Zheng's results [Electronic version]. Personality and Social Psychology Bulletin, 25, 1045-1048.

Electronic materials that are NOT duplicates of print sources


For electronic materials that are NOT duplicates of print sources (e.g., an organization's web site, an electronic-only journal, etc.), you must provide a retrieval date (because such an electronic source may not be stable; i.e., it may change) and a URL.


Nelson, G., Westhues, A., & MacLeod, J. (2003, December 18). A meta-analysis of longitudinal research on preschool prevention programs for children. Prevention & Treatment 6, Article 31. Retrieved December 2, 2004, from http://journals.apa.org/prevention/volume6/pre0060031a.html

Dunbar, C. (2004, November 29). Aging in place gracefully. Nursing Spectrum. Retrieved December 2, 2004, from http://community.nursingspectrum.com/MagazineArticles/ article.cfm?AID=13219

Because APA guidelines for citing electronic sources are constantly evolving, for the most current principles and samples, you should consult the APA's own website: https://apastyle.apa.org/.

Format the references list
Title: Type the word "References" at the top of a new page, centered.
Spacing: All entries should be double-spaced, unless your assignment instructs you otherwise.
Indentation: Although the current Publication Manual advises standard (five spaces, first line) indention for the references list, this is primarily designed to make typesetting easier; the typeset version will have hanging indents (first line flush left, following lines five spaces indent). If your final version will be turned in for a grade rather than publication, we recommend that you use hanging indents for enhanced readability. We have formatted our sample references list with hanging indents.
Capitalization: Capitalize only the first word of titles of books and articles and the first word after a colon.
Punctuation: Use a comma to separate:

  • surnames from initials
  • a newspaper title from p. or pp.
  • a journal title from volume number
  • a volume number from page numbers
  • when given, an issue number from page numbers
  • (Ed.) from book title
  • city of publication from state