The most common system of documentation used in the social sciences is the author-date system of the American Psychological Association (APA).

General APA Bibliographic form:

• For each author, list in order of authorship, author's last name, followed by a comma and initials of first and middle name. Do not use authors' first names.
• The first author's last name is flush with left margin on first line; indent each subsequent line.
• Use "&" to join names of two or more authors. Do not write out "and."
• Place year of publication in parentheses after author(s).
• Place periods between major divisions and at the end.
• Italicize the title of the source (e.g., book, journal).
• If a work is subtitled place a colon between title and subtitle. Capitalize only the first word of title and subtitle (except for proper nouns).
• For books, include the place of publication and publisher, separated by a colon.
• For articles in journals, Italicize journal/magazine title. Capitalize all major words, followed by volume number and inclusive pages, all of which are separated by commas. Italicize the volume number.
• Center the word "References" at the top of your list of references. Include all references you have cited in the text and only these references. 
• Single-space within entries; double-space between entries.
• Alphabetize list of references by authors' last names. If a reference has no author, alphabetize by the first word of the article (excluding "a," "an," "the").

Example of citations in APA format

Book:

Garrod, A., Smulyan, L., Powers, S., & Kilkenny, R. (2008). Adolescent portraits: Identity, relationships, and challenges (6th ed.). Boston: Allyn and Bacon.

Chapter in an edited book:

Flavell, J. H. (1976). Metacognitive aspects of problem solving. In L. B. Resnick (Ed.), The nature of intelligence (pp. 231-35). Hillsdale, N.J.: Erlbaum.

Journal article:

Tronick, E. A. (1989). Emotions and emotional communication in infants. American Psychologist, 44, 112-119.

For information on MLA bibliographic format, click here.

APA GUIDELINES FOR INTERNAL CITATIONS

In APA formatting, each paraphrase, summary, quotation, study, etc. is followed by a parenthetical containing the last name (s) of the author (s) and the date of the publication.  Each piece of information inside the parentheses is separated by a comma. When you mention the authors names in the text, join multiple authors with "and" not "&."  The following would be an example of textual references in the APA system:

The primary characteristics of motherese are exaggerated intonation, high pitch, and frequent repetition (Snow, 1976).

Only put the page number in the citation if you are using a direct quote.

Metacognition has been defined as "knowledge that takes as its object or regulates any aspect of cognitive endeavor" (Flavell, 1984, p.353).

Do not use an author's first name unless you are citing works by two different authors of the same last name.

      WRONG:         Katherine Nelson (1988) has discussed...

      RIGHT:            Nelson (1988) has discussed...

In general, do not cite the journal or book title in your discussion.

      WRONG:         Nelson (1988) in her book Event Knowledge examines the role...           

      RIGHT:            Nelson (1988) examines the role...

When you clearly mention the author and/or the date in the text, you do not need to repeat the information in the parenthetical citation. One work by a single author--three examples:

      Smith (1983) compared reaction times...

      In a recent study of reaction times (Smith, 1983)...

      In 1983, Smith compared...

When a work has two authors, always cite both names every time the reference occurs.

When a work has three, four, or five authors, cite all the names the first time the reference occurs; in subsequent citations, include only the name of the first author followed by et al.  For example,

      Garrod, Smulyan, Powers, and Kilkenny (2008) note that...   (first citation)

      Garrod et al. (2008) note that...                                             (subsequent citation) 

For two or more works by different authors include the in-text citations alphabetically:

      Several studies (Dorow & Neal, 1979; Mullany, 1978; Smith, 1983) have...