Purdue Online Writing Lab College of Liberal Arts
Reference List: Author/Authors
Welcome to the Purdue OWL
This page is brought to you by the OWL at Purdue University. When printing this page, you must include the entire legal notice.
Copyright ©1995-2018 by The Writing Lab & The OWL at Purdue and Purdue University. All rights reserved. This material may not be published, reproduced, broadcast, rewritten, or redistributed without permission. Use of this site constitutes acceptance of our terms and conditions of fair use.
Note: This page reflects the latest version of the APA Publication Manual (i.e., APA 7), which released in October 2019. The equivalent resource for the older APA 6 style can be found here .
The following rules for handling works by a single author or multiple authors apply to all APA-style references in your reference list, regardless of the type of work (book, article, electronic resource, etc.).
Note: Because the information on this page pertains to virtually all citations, we've highlighted a few important differences between APA 6 and APA 7 with underlined notes written in red.
Single Author
Last name first, followed by author initials.
Ahmed, S. (2012). On being included: Racism and diversity in institutional life . Duke University Press.
Two Authors
List by their last names and initials. Separate author names with a comma. Use the ampersand instead of "and."
Soto, C. J., & John, O. P. (2017). The next big five inventory (BFI-2): Developing and assessing a hierarchical model with 15 facets to enhance bandwidth, fidelity, and predictive power. Journal of Personality and Social Psychology , 113 (1), 117-143. http://dx.doi.org/10.1037/pspp0000096
Three to Twenty Authors
List by last names and initials; commas separate author names, while the last author name is preceded again by ampersand. This is a departure from APA 6, which only required listing the first six authors before an ellipsis and the final author's name.
Nguyen, T., Carnevale, J. J., Scholer, A. A., Miele, D. B., & Fujita, K. (2019). Metamotivational knowledge of the role of high-level and low-level construal in goal-relevant task performance. Journal of Personality and Social Psychology, 117 (5), 879-899. http://dx.doi.org/10.1037/pspa0000166
More Than Twenty Authors
List by last names and initials; commas separate author names. After the first 19 authors’ names, use an ellipsis in place of the remaining author names. Then, end with the final author's name (do not place an ampersand before it). There should be no more than twenty names in the citation in total.
Pegion, K., Kirtman, B. P., Becker, E., Collins, D. C., LaJoie, E., Burgman, R., Bell, R., DelSole, R., Min, D., Zhu, Y., Li, W., Sinsky, E., Guan, H., Gottschalck, J., Metzger, E. J., Barton, N. P., Achuthavarier, D., Marshak, J., Koster, R., . . . Kim, H. (2019). The subseasonal experiment (SubX): A multimodel subseasonal prediction experiment. Bulletin of the American Meteorological Society , 100 (10), 2043-2061. https://doi.org/10.1175/BAMS-D-18-0270.1
Group Author
Group authors can include corporations, government agencies, organizations, etc; and a group may publish in coordination with individuals. Here, you simply treat the publishing organization the same way you'd treat the author's name and format the rest of the citation as normal. Be sure to give the full name of the group author in your reference list, although abbreviations may be used in your text.
Entries in reference works ( e.g. dictionaries, thesauruses, and encyclopedias) without credited authors are also considered works with group authors.
Merriam-Webster. (2008). Braggadocio. In Merriam-Webster’s Advanced Learner’s English Dictionary . Merriam-Webster.
When a work has multiple layers of group authorship (e.g. The Office of the Historian, which is a part of the Department of State, publishes something), list the most specific agency as the author and the parent agency as the publisher.
Bureau of International Organization Affairs. (2018). U.S. contributions to international organizations, 2017 [Annual report]. U.S. Department of State. https://www.state.gov/u-s-contributions-to-international-organizations/
Unknown Author
When the work does not have an author move the title of the work to the beginning of the references and follow with the date of publication. Only use “Anonymous ” if the author is the work is signed “Anonymous.” This is a new addition to APA 7.
Merriam-Webster's collegiate dictionary (11th ed.). (2003). Merriam-Webster.
NOTE : When your essay includes parenthetical citations of sources with no author named, use a shortened version of the source's title instead of an author's name. Use quotation marks and italics as appropriate. For example, parenthetical citations of the source above would appear as follows: ( Merriam-Webster's , 2003).
Two or More Works by the Same Author
Use the author's name for all entries and list the entries by the year (earliest comes first). List references with no dates before references with dates.
Urcuioli, P. J. (n.d.).
Urcuioli, P. J. (2011).
Urcuioli, P. J. (2015).
When an author appears both as a sole author and, in another citation, as the first author of a group, list the one-author entries first.
Agnew, C. R. (Ed.). (2014). Social influences on romantic relationships: Beyond the dyad . Cambridge University Press.
Agnew, C. R., & South, S. C. (Eds.). (2014). Interpersonal relationships and health: Social and clinical psychological mechanisms. Oxford University Press.
References that have the same first author and different second and/or third authors are arranged alphabetically by the last name of the second author, or the last name of the third if the first and second authors are the same.
Arriaga, X. B., Capezza, N. M., Reed, J. T., Wesselman, E. D., & Williams, K. D. (2014). With partners like you, who needs strangers?: Ostracism involving a romantic partner. Personal Relationships, 21(4) , 557-569.
Arriaga, X. B., Kumashiro, M., Finkel, E. J., VanderDrift, L. E., & Luchies, L. B. (2014). Filling the void: Bolstering attachment security in committed relationships. Social Psychological and Personality Science, 5 (4), 398-405.
Two or More Works by the Same Author in the Same Year
If you are using more than one reference by the same author—or the same group of authors listed in the same order—published in the same year, first check to see if they have more specific dates ( this recommendation is new to APA 7) . Works with only a year should be listed before those with a more specific date. List specific dates chronologically. If two works have the same publication date, organize them in the reference list alphabetically by the title of the article or chapter. If references with the same date are identified as parts of a series (e.g. Part 1 and Part 2), list them in order of their place in the series. Then assign letter suffixes to the year. Refer to these sources in your essay as they appear in your reference list, e.g.: "Berndt (2004a) makes similar claims..."
Berndt, T. J. (2004a). Children’s friendships: Shifts over a half-century in perspectives on their development and their effects. Merrill Palmer Quarterly, 50 (3) , 206-223.
Berndt, T. J. (2004b). Friendship and three A’s (aggression, adjustment, and attachment). Journal of Experimental Child Psychology, 88 (1) , 1-4.
Introductions, Prefaces, Forewords, and Afterwords
Cite the publishing information about a book as usual, but cite Introduction, Preface, Foreword, or Afterword (whatever title is applicable) as the chapter of the book.
Lang, J. M. (2018). Introduction. In Dujardin, G., Lang, J. M., & Staunton, J. A. (Eds.), Teaching the literature survey course (pp. 1-8). West Virginia University Press.
IMAGES
VIDEO
COMMENTS
Webpage or Piece of Online Content ... If the resource was written by a group or organization, use the name of the group/organization as the author. Additionally
Please use the example at the bottom of this page to cite the Purdue OWL in APA. Cite your source automatically in APA. Website
Individual webpages and documents hosted online are cited similarly to print content. Note, however, that the URL is typically included at the end of the entry.
These OWL resources will help you learn how to use the American Psychological Association (APA) citation and format style. This section contains resources
This website collects and publishes the ideas of individuals who have contributed those ideas in their capacities as faculty-mentored student scholars.
Reference List. Resources on writing an APA style reference list, including citation formats. Cite your source automatically in APA.
When using APA format, follow the author-date method of in-text citation. This means that the author's last name and the year of publication for the source
Titles of books and reports are italicized; titles of articles, chapters, and web pages are in quotation marks.” For example, a parenthetical citation for an
Titles of books and reports are italicized; titles of articles, chapters, and web pages are in quotation marks. APA style calls for capitalizing important
Note: Because the information on this page pertains to virtually all citations, we've highlighted a few important differences between APA 6 and APA 7 with