APA Citation Style

American Psychological Association (APA) style is a widely accepted style of documentation, particularly in the social sciences. APA style specifies the names and order of headings, formatting, and organization of citations and references, and the arrangement of tables, figures, footnotes, and appendices, as well as other manuscript and documentation features.  

APA style uses the author-date style of parenthetical referencing, with such source citations keyed to a subsequent list of "References." Also known as the Harvard Style^[1]. The APA Publication Manual provides basic guidelines for documenting both print and electronic resources. The section on electronic resources is updated and supplementd by the APA Style Guide to Electronic References (APA, 2007).

The sixth edition was published by the American Psychological Association in July 2009. It offers new and expanded instruction on publication ethics, statistics, journal article reporting standards, electronic reference formats, and the construction of tables and figures. Due to some changes in some areas from the previous edition, such as References, the information listed below should be used with caution as it does not reflect the most recent edition of the Publication Manual.

Reference citations in text are done using parenthetical referencing. Most usually, this involves enclosing the author's surname and the date of publication within parentheses, separated by a comma, generally placed immediately after the reference or at the end of the sentence in which the reference is made. 

However, it is also common for the authors to be the subject or object of a sentence. In such a case only the year is in parenthesis. In all cases of citation, author name(s) are always followed immediately by a year, and years are never presented without author name(s) immediately preceding it. In the case of a quotation, the page number is also included in the citation.

Full bibliographic information is then provided in a Reference section at the end of the article. APA style defines that the reference section may only include articles that are cited within the body of an article. This is the distinction between a document having a Reference section and a bibliography, which may incorporate sources which may have been read by the authors as background but not referred to or included in the body of a document.

1. Single author

Format should be Author's last name followed directly by a comma, then the year of publication. When one makes the reference to the author(s) directly as a part of the narrative, then only the year (and page number if needed) would remain enclosed within parentheses. The same holds for multiple authors.

A recent study found a possible genetic cause of alcoholism (Pauling, 2005).

Pauling (2005) discovered a possible genetic cause of alcoholism.

2. Two authors

Authors should be presented in order that they appear in the published article. If they are cited within closed parentheses, use the ampersand (&) between them. If not enclosed in parentheses then use expanded "and".

A recent study found a possible genetic cause of alcoholism (Pauling & Liu, 2005).

Pauling and Liu (2005) discovered a possible genetic cause of alcoholism.

3. Three to five authors no

With three to five authors, the first reference to an article includes all authors. Subsequent citations in the same document may refer to the article by the principal author only plus "et al." However, all authors must be present in the references section.

A recent study found a possible genetic cause of alcoholism (Pauling, Liu, & Guo, 2005).

Pauling, Liu, and Guo (2005) conducted a study that discovered a possible genetic cause of alcoholism.

Pauling et al. (2005) discovered a possible genetic cause of alcoholism.

A recent study found a possible genetic cause of alcoholism (Pauling et al., 2005).

4. Six authors or more

The correct format is (First Author et al., Year). In the reference section, all six authors' names should be included.

Pauling et al. (2005) discovered a possible genetic cause of alcoholism.

5. Multiple publications, same author

If an author has multiple publications that you wish to cite, you use a comma to separate the years of publication in chronological order (oldest to most recent). If the publications occur in the same year, the Publication Manual recommends using suffixes a, b, c, etc. (note that corresponding letters should be used in the reference list, and these references should be ordered alphabetically by title).

Recent studies have found a possible genetic cause of alcoholism (Pauling, 2004, 2005a, 2005b).

Pauling (2004, 2005a, 2005b) has conducted studies that have discovered a possible genetic cause of alcoholism

6. Multiple publications, different authors

Follow the rules for one author above, and use a semicolon to separate articles. Citation should first be in alphabetical order of the author, then chronological.

Recent studies found a possible genetic cause of alcoholism (Alford, 1995; Pauling, 2004, 2005; Sirkis, 2003)

7. Direct quotes

The same rules as above apply here, the format being (Author, Year, Page Number).

When asked why his behavior had changed so dramatically, Max simply said, "I think it's the reinforcement" (Pauling, 2004, p. 69).

 

 

 APA Citation Style

Publication Manual of the American Psychological Association, 5th edition, 2001
APA Style Guide to Electronic References, 2007

Follow these color codes:
Author(s)	Date	Title of Book	Title of Article	Title of Periodical
Volume	Pages	Place of Publication	Publisher	Other Information