One author
Two authors
Three-five authors
Six or more authors
Multiple works by the same author
Authors with same surname
Organizations as authors
Works without authors
Works with anonymous listed as author
Works without dates
Works without pagination
Personal communications
Secondary sources
Direct quotations
Multiple citations by the same author in one paragraph
When listing the source of information you are using in your paper, list the last name of the author (without their initials), followed by a comma, and then the year of publication. When referring to the author(s) directly in the text (also called a narrative citation), then list only the year (and page number, if needed for a direct quote).
Give the author's name and the year of publication. If the author's name is stated in the sentence, always place the year in parentheses immediately after the name.
Several studies show a correlation between deforestation and groundwater degradation (Clark, 1998).
Clark's (1998) study shows that . . .
Give both names separated by the word and when including the names in the text of a sentence. For citations in parentheses use an ampersand (&). Authors should be presented in the order that they appear in the published article. If they are cited within closed brackets, use the ampersand (&) between them. If they are not enclosed in brackets, then use the spelled out “and.”
Ultimately, results were inconclusive (Flannigan & McBride, 2001).
Flannigan and McBride (2001) state the results...
Starting with the first author mentioned in the text, the correct format is (Author et al., year). This includes even the first citation. All authors, up to 20, should be listed in the corresponding reference.
The exercise was no fun at all (Sawyer et al., 2010).
Sawyer et al. (2010) were quick to point out...
Group author
For group authors without abbreviations, simply list the group author with the usual citation format.
According to Harvard University (2019), poorer college students face many obstacles as they work to complete their degrees.
Financially challenged students face many obstacles as they work to complete their degrees (Harvard University, 2019).
Group author with abbreviation
For group authors with abbreviations, use the full name and the abbreviation in the first citation. Then, use only the abbreviation in subsequent citations.
FIRST citation: (National Library of Medicine [NLM], 2005)...
National Library of Medicine [NLM], (2005) stated...
SUBSEQUENT citations: (NLM, 2005)
NLM (2005)
When the author of a work is not known, the title of the work will be used in place of the author. But,
Place the abbreviation n.d. (for no date) in place of the year for in-text citations and the reference list.
Brigmeyer (n.d.) associates...
(Brigmeyer, n.d.).
Personal communications (interviews, e-mail correspondence, lectures, etc.) should be used sparingly. When citing personal communications only cite this material in text, do not include personal communication citations in the reference list. They are excluded from the reference list because this is unrecoverable data.
When citing a personal communication within the text, include the following information: (Author’s first initial. Author’s last name, personal communication, Date of publication).
One student (A. M. Mavin, personal communication, January 28, 2007) expressed horror...
Mavin still maintains his innocence (personal communication, April 15, 2009).
Type of Citation |
First Citation in Text |
Subsequent Citations in Text |
Parenthetical Format, First Citation in Text |
Parenthetical Format, Subsequent Citations in Text |
1 work by 1 author |
Harris (2003) |
Harris (2003) |
(Harris, 2003) |
(Harris, 2003) |
1 work by 2 authors |
Harris and Ramirez (2011) |
Harris and Ramirez (2011) |
(Harris & Ramirez, 2011) |
(Harris & Ramirez, 2011) |
1 work by 3 or more authors |
Peet et al. (2018) |
Peet et al. (2018) |
(Peet et al., 2018) |
(Peet et al., 2018) |
Groups (readily identified through abbreviations) as authors |
National Oceanic and Atmospheric Administration (NOAA, 2017) |
NOAA (2017) |
(National Oceanic and Atmospheric Administration [NOAA], 2017) |
(NOAA, 2017) |
Groups (no abbreviation) as authors |
Stanford University (2010) |
Stanford University (2010) |
(Stanford University, 2010) |
(Stanford University, 2010) |
American Psychological Association. (2009). Crediting sources: Citing references in text. Publication manual of the American psychological association (6th ed., p. 177) Washington, D.C.: Author.