PERRLA/Guides/APA 7/Encyclopedia entry

How to Cite an Encyclopedia Entry in APA 7

An APA 7 encyclopedia entry reference lists the entry's author, the date in parentheses, the entry title in sentence case, the word In, any editors with (Ed.) or (Eds.), the encyclopedia's title in italics with its edition, the publisher, and the DOI or URL. An online encyclopedia that keeps changing and isn't archived, like Encyclopaedia Britannica, adds "Retrieved Month Day, Year, from" before the URL. The in-text citation is the author's last name and the year: (Eyal, 2025).

The format

Author, A. A. (Year). Title of entry. In E. E. Editor (Ed.), Title of encyclopedia (xth ed., pp. xx–xx). Publisher. https://doi.org/xxxx

PERRLA APA Experts · Updated October 21, 2026
Checked against the Publication Manual of the American Psychological Association, 7th edition. Every example is formatted by PERRLA's reference engine.

First, the easy way: PERRLA

Paste a Britannica link into PERRLA's reference search. PERRLA files it as an entry in an encyclopedia and fills in the writer, the entry title in sentence case, Encyclopaedia Britannica as the reference work, the entry's date, and the link. Britannica entries change and aren't archived, so click Today on the Retrieval Date before you save.

For an entry written by Britannica's editors, check two things first. Change the contributor to Group Author (Organization) and type Encyclopaedia Britannica. Then make the date the one shown under the entry's title, the day it was last updated.

Have a DOI for an entry in a print or e-book encyclopedia, like Springer's Encyclopedia of Behavioral Medicine? Paste the DOI. PERRLA builds it as a chapter in an edited book, which the APA format treats the same way, with the author, the editor, the encyclopedia's title, the page range, the publisher, and the DOI. Add the edition if the encyclopedia has one.

Adding one by hand, like a Stanford Encyclopedia of Philosophy entry? Choose Reference Work, then Entry in a reference work, and pick Entry in an encyclopedia. Add the entry's author and the encyclopedia's editors, then fill in the Entry Title, the Reference Work Name, the publisher, the Publication Year, and the Edition (type Spring 2025 for a Stanford edition). Paste the archived URL. For an entry in a print encyclopedia, add the entry's page range too, and PERRLA puts it in the same parentheses as the edition: (2nd ed., pp. 999–1000). PERRLA handles the italics, the "In," the (Eds.), and the "Retrieved ..., from" wording.

Not using PERRLA yet? Here is how to build the same reference by hand.

The parts of the reference

1. Author

Start with the person who wrote the entry: last name, a comma, and initials. Scholarly encyclopedias like the Stanford Encyclopedia of Philosophy name a writer for every entry.

Eyal, N.

Britannica names a writer on many entries. Check the entry's References & Edit History page: the name under Primary Contributors is the author. When the primary contributor is Britannica's own staff, the encyclopedia is the group author.

Encyclopaedia Britannica.

No author at all? Move the entry title to the front, before the date. The in-text citation then uses the entry title in quotation marks, in title case, with the year.

2. Date

Put the date in parentheses, followed by a period. Print and edited encyclopedias take the year of the edition you used.

(2020).

An online encyclopedia that shows when an entry was last updated gets that date, written year first.

(2026, September 18).

For the Stanford Encyclopedia of Philosophy, use the year of the archived edition you cite, not the year the entry was first published. No date anywhere? Write (n.d.).

3. Entry title

Write the entry title in sentence case: capitalize the first word, the first word after a colon, and proper nouns. Don't italicize it or put it in quotation marks. End it with a period.

Health beliefs/health belief model.

Encyclopedias often print entry titles in title case. Change them to sentence case. Names of people stay capitalized: Florence Nightingale.

4. In and the editors

Write In before the encyclopedia's title. If the encyclopedia names editors, put them after In, initials first, followed by (Ed.) for one or (Eds.) for two or more, then a comma.

In E. N. Zalta & U. Nodelman (Eds.),

Online encyclopedias like Britannica don't list editors for each entry, so the reference goes straight from In to the title.

5. Encyclopedia title and edition

Write the encyclopedia's title in italics and in sentence case, keeping proper nouns capitalized. Put the edition in parentheses after it, not italicized. Stanford Encyclopedia of Philosophy editions are named by season and year.

The Stanford encyclopedia of philosophy (Spring 2025 ed.).

For a print encyclopedia, the APA format puts the entry's page range in the same parentheses as the edition, separated by a comma: (2nd ed., pp. 999–1000). A multivolume set adds the volume number before the pages.

6. Publisher

Give the publisher's name after the parentheses, followed by a period. Leave out the city and words like Inc.

Metaphysics Research Lab, Stanford University.

When the publisher is the same as the group author, list the name once, as the author. The Britannica examples on this page leave the publisher out, since its name is already the encyclopedia's title.

7. Retrieval date and URL or DOI

End with the DOI as a link when the entry has one. Otherwise end with the entry's URL. Don't put a period after either.

https://doi.org/10.1007/978-3-030-39903-0_1227

An online entry that can change and isn't archived needs a retrieval date: the day you read it, written "Retrieved Month Day, Year, from" and then the URL.

Retrieved October 21, 2026, from https://www.britannica.com/biography/Florence-Nightingale

An archived version, like a Stanford Encyclopedia of Philosophy edition, never changes, so it takes no retrieval date.

Examples

An entry in the Stanford Encyclopedia of Philosophy

Nir Eyal's entry on informed consent, a staple of nursing and research ethics courses. The Stanford Encyclopedia asks you to cite a fixed, archived edition, so this reference uses the Spring 2025 archive (the entry was first published in 2011 and last revised in February 2025) and needs no retrieval date.

  • Parenthetical citation(Eyal, 2025)
  • Narrative citationEyal (2025)

A Britannica entry with a named writer

Britannica's entry on Florence Nightingale names Louise Selanders, a professor emerita of nursing at Michigan State University, as its primary contributor. Britannica updates entries without archiving the old versions, so the reference gives the last-updated date and a retrieval date.

  • Parenthetical citation(Selanders, 2026)
  • Narrative citationSelanders (2026)

A Britannica entry written by its editors

Britannica's entry on the Hippocratic oath lists The Editors of Encyclopaedia Britannica as its primary contributor, so the encyclopedia itself is the group author.

  • Parenthetical citation(Encyclopaedia Britannica, 2026)
  • Narrative citationEncyclopaedia Britannica (2026)

An entry in an edited encyclopedia with a DOI

Tana M. Luger's entry on the health belief model in the second edition of Springer's Encyclopedia of Behavioral Medicine, edited by Marc D. Gellman. The entry runs from page 999 to page 1000 in print and has its own DOI.

  • Parenthetical citation(Luger, 2020, p. 999)
  • Narrative citationLuger (2020, p. 999)

In-text citations

An APA 7 in-text citation for an encyclopedia entry gives the entry's author and the year, never the encyclopedia's editors when the entry has its own author.

  • One author: (Eyal, 2025) or Eyal (2025)
  • Britannica with a named writer: (Selanders, 2026)
  • Britannica's editors: (Encyclopaedia Britannica, 2026)
  • A quote from a print entry: add the page: (Luger, 2020, p. 999)
  • No author: the entry title in quotation marks and title case, with the year or n.d.

Online entries have no page numbers. To quote one, give the section heading or count the paragraphs and add the paragraph number, like para. 3.

Common mistakes

  • https://plato.stanford.edu/entries/informed-consent/https://plato.stanford.edu/archives/spr2025/entries/informed-consent/The live address shows whatever the entry says today. The Stanford Encyclopedia asks you to cite an archived edition, which never changes, so your reader sees the version you read.
  • Eyal, N. (2011). Informed consent.Eyal, N. (2025). Informed consent.2011 is when the entry first appeared. The date goes with the version you cite: the year of its archived edition.
  • Britannica Editors. (2026, August 10). Hippocratic oath.Encyclopaedia Britannica. (2026, August 10). Hippocratic oath."Britannica Editors" is the staff byline. When Britannica's editors are the primary contributor, the organization is the group author.
  • Florence Nightingale. Encyclopaedia Britannica.Florence Nightingale. In Encyclopaedia Britannica.An entry is part of a larger work. The word In tells your reader the italic title is the encyclopedia, not the entry.
  • In Encyclopaedia Britannica. https://www.britannica.com/biography/Florence-NightingaleIn Encyclopaedia Britannica. Retrieved October 21, 2026, from https://www.britannica.com/biography/Florence-NightingaleBritannica changes its entries and doesn't keep the old versions. The retrieval date tells your reader which day's version you read.
  • Health Beliefs/Health Belief Model.Health beliefs/health belief model.Entry titles take sentence case in the reference, even when the encyclopedia prints them in title case.

Quick checklist

  • The entry's own author, or the organization when its staff wrote it
  • The year of the edition, or the last-updated date for an online entry
  • Entry title in sentence case, not italic
  • In, then any editors with (Ed.) or (Eds.)
  • Encyclopedia title in italics, with the edition (and pages, for print) in parentheses
  • The archived URL for the Stanford Encyclopedia of Philosophy
  • A retrieval date for Britannica and other entries that change

Questions students ask

Do I need a retrieval date for an encyclopedia entry?

Only when the entry can change and the old version isn't kept, like a Britannica entry. Then write "Retrieved Month Day, Year, from" before the URL, with the day you read it. Print entries, entries with a DOI, and archived editions like the Stanford Encyclopedia of Philosophy's don't need one.

What date do I use for a Stanford Encyclopedia of Philosophy entry?

The year of the archived edition you cite. On the entry, click Author and Citation Info. It names the archive (like Spring 2025) and gives its URL. The edition name goes in parentheses after the encyclopedia's title, and the URL ends the reference.

Who is the author of a Britannica article?

Open the entry's References & Edit History page and look under Primary Contributors. If a person is listed, like Louise Selanders for Florence Nightingale, that person is the author. If it lists The Editors of Encyclopaedia Britannica, use Encyclopaedia Britannica as the group author.

How do I cite a print encyclopedia?

The same way, without the URL. Give the entry's author, the year of the edition, the entry title, In, the editors, and the encyclopedia's title. Then put the edition, the volume for a multivolume set, and the page range in one set of parentheses, followed by the publisher.

Is the encyclopedia's editor the author of the entry?

No. When an entry has its own author, that author goes first and in your in-text citation. The editors go after In, with (Ed.) or (Eds.). Use the editors in the author spot only when you cite the whole encyclopedia.

Is a Wikipedia article cited the same way?

Close, but not quite. Wikipedia articles have no author, so the article title goes first, and you cite the permanent link to the version you read, with that version's date. See the Wikipedia guide for the details.

Rules checked against the Publication Manual of the American Psychological Association (7th ed.), Sections 8.14, 8.28, 9.11, 9.12, 9.14, 9.16, 9.29, 9.34, and 10.3, and the APA Style website's dictionary entry reference examples. Example sources verified on October 21, 2026, at the Stanford Encyclopedia of Philosophy's citation page for the entry, Britannica's References & Edit History pages, and Springer Nature Link.

PERRLA builds an encyclopedia entry reference from a Britannica link or a DOI, with the In, the italics, and the editors in place.

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