Written and maintained by CASRAI Editorial Board
Last updated
A book with two authors is cited with both names in every major style. What changes between styles is the joining word, the way the names are written, and the point at which a longer author list is cut down to “et al.” Two authors sit below that point in APA, MLA, Chicago and Harvard, so neither name is dropped.
The format: how to cite a book with two authors
Every style asks for the same core elements: both authors, the year, the title, and the publisher. The differences are in the details below. The books in every example on this page are fictitious and are labelled as examples; they are not real works or people.
- APA 7th edition (2020): Author, A. A., & Author, B. B. (Copyright Year). Title of the book (7th ed.). Publisher. DOI or URL. Both names are inverted, with initials, and an ampersand comes before the last author. Capitalize only the first word of the title and subtitle and proper nouns, and leave out the publisher’s location.
- MLA 9th edition (2021): Last, First, and First Last. Title of Book. Publisher, Year. Only the first author is inverted; the second author is written in normal order and joined by the word “and”.
- Chicago 18th edition (2024): both authors are named in full in a note and in an author-date text citation, and up to six authors are listed in a bibliography or reference-list entry.
- Harvard (Cite Them Right variant): Surname, Initial. and Surname, Initial. (Year) Title. Edition (if not the first). Publisher. Harvard has no single official manual, so name the variant you follow.
Examples of a book by two authors
How to cite a book by two authors in APA 7
Example (fictitious book): Smith, J., & Lee, K. (2024). Writing for review boards (2nd ed.). Example Press.
How to cite a book with 2 authors in MLA 9
Example (fictitious book): Alder, Mara, and Tomas Reyes. Lab Notebooks in Practice. Harbor UP, 2019.
The same pattern appears in a published university-library example: Dobson, Kit, and Smaro Kamboureli. Producing Canadian Literature: Authors Speak on the Literary Marketplace. Wilfrid Laurier UP, 2012.
How to cite a book with two authors in Harvard
Example (fictitious book): Smith, J. and Lee, K. (2020) Studying citation habits. Example Press. The two authors are joined by “and”, and the edition is added only when it is later than the first.
How to cite a book with two authors in Chicago 18
Chicago 18th edition names both authors in a note and in an author-date text citation, and lists both in the bibliography or reference list, because notes and text citations name up to two authors and lists name up to six. For the exact element order of a Chicago book entry, follow the book examples in the Chicago Manual of Style itself.
In-text citation version
- MLA: both surnames joined by “and”, then the page number with no comma and no “p.”: (Alder and Reyes 42). The MLA Style Center states that when a work has two authors, “both authors’ names must be included in prose or parentheses in the in-text citation” and gives (Buurma and Heffernan) as its example form.
- Harvard (Cite Them Right): both surnames joined by “and” with the year: (Shah and Papadopoulos, 2015).
- Chicago 18 (notes or author-date text citations): up to two authors are listed, so both names appear; with more than two, only the first author is named, followed by “et al.”
- APA 7: “et al.” applies from three authors onward, in every in-text citation including the first; a source with two authors is below that threshold and keeps both names.
For the underlying idea of a bracketed source pointer, see parenthetical citation. APA in-text behaviour for several authors is covered in multiple authors in-text citation in APA.
How to cite books with multiple authors: where two becomes three
Two authors is the case where nothing is shortened. The thresholds below show where each style starts to cut a longer list.
| Style | Two authors | Where “et al.” starts |
|---|---|---|
| APA 7 | Both names in the reference list, joined by an ampersand | In text: three or more authors (first author + et al.). Reference list: all authors up to 20 |
| MLA 9 | Both names in the entry and in text, joined by “and” | Three or more authors: first author + et al. |
| Chicago 18 | Both names in notes and author-date text; both in the list | Text and notes: more than two authors. Bibliography or reference list: more than six authors (first three, then et al.) |
| Harvard (CTR) | Both names in text, joined by “and” | In text: four or more authors. Other Harvard variants set different thresholds |
For a wider comparison of et al. thresholds, see et al. in references. MLA’s three-or-more rules are worked through in how to cite multiple authors in MLA.
Common errors
- Dropping the second author. A two-author book needs both names in MLA, Harvard and Chicago text citations.
- Mixing joining words. APA reference lists use an ampersand before the last author; MLA and Harvard use the word “and”. Do not carry one style’s joiner into another.
- Inverting both names in MLA. Only the first author is inverted: Alder, Mara, and Tomas Reyes, not Alder, Mara, and Reyes, Tomas.
- Adding “p.” in MLA in-text citations. MLA gives the number alone.
For manuscripts and theses
Use the style your journal, publisher or graduate school names, and apply its author-count rule to every entry in the same way. A journal’s author instructions can override the general pattern, for example by asking you to list all authors. If you are moving a manuscript from one style to another, the two-author book is a quick check: the joiner, the name inversion and the title capitalization all change. For a single book from start to finish, see how to cite from a book; for MLA specifically, see MLA citation for a book.
Style-guide edition
This page follows APA 7th edition (2020), MLA 9th edition (2021) and Chicago Manual of Style 18th edition (2024), the current editions as of October 2026. The Chicago author-count rules come from “What’s New in the 18th Edition” on the Chicago Manual of Style site (sections 13.23 and 13.107), checked 2026-10-29. The APA patterns come from the APA Style reference guide and reference examples PDFs, last updated March 2026, checked 2026-10-28. Harvard is shown in the Cite Them Right variant, as published in university library guides.
FAQ
How do I cite a book by two authors?
Name both authors. In APA, write Smith, J., & Lee, K. (2024). Title. Publisher.; in MLA, write Alder, Mara, and Tomas Reyes. Title. Publisher, Year. Do not use “et al.” for two authors in any of the styles above.
How do I cite books with multiple authors?
Two authors are always both named. At three or more, MLA uses the first author plus “et al.”, and APA uses it in text; Chicago does so in notes and text citations beyond two authors and in the bibliography beyond six. See the table above.
How do I cite a book with 2 authors in text?
In MLA, (Alder and Reyes 42). In Harvard Cite Them Right, (Shah and Papadopoulos, 2015). In Chicago 18, both names appear because notes and author-date citations list up to two authors.
Do I use “&” or “and” between two authors?
It depends on the style. The APA reference-list pattern uses an ampersand before the last author. MLA and Cite Them Right Harvard use “and”.
Sources
- Chicago Manual of Style Online, What’s New in the 18th Edition: https://www.chicagomanualofstyle.org/help-tools/what-s-new.html (checked 2026-10-29).
- APA Style, Reference Guide (last updated 23 March 2026): https://apastyle.apa.org/instructional-aids/reference-guide.pdf and Reference Examples (last updated 3 March 2026): https://apastyle.apa.org/instructional-aids/reference-examples.pdf (checked 2026-10-28).
- MLA Style Center, Quiz: Complex In-Text Citations: https://style.mla.org/quiz-complex-in-text-citations/ (checked 2026-10-29).
- Concordia University, St. Paul, MLA 9th Edition Citation Guide, Multiple Authors: https://library.csp.edu/mla/multipleauthors and University of Lethbridge Library, MLA Citation Style, 9th Edition, Books: https://library.ulethbridge.ca/mlastyle9/books/multiple (both checked 2026-10-29).
- Open University Library, Quick guide to Harvard referencing (Cite Them Right): https://university.open.ac.uk/library/referencing-and-plagiarism/quick-guide-to-harvard-referencing-cite-them-right and Newcastle University, Cite Them Right Harvard Style Sheet (August 2025): https://www.ncl.ac.uk/mediav8/academic-skills-kit/file-downloads/manage-info/2025%20Cite%20Them%20Right%20Harvard%20Style%20Sheet.pdf (checked 2026-10-28).
