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.

Two Authors

List by their last names and initials. Separate author names with a comma. Use the ampersand instead of "and."

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.

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.

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.

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.

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.

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.

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.

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.

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..."

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.