Which edition of a book should you cite?

Sometimes students notice that a newer version of the book they need to cite has been published, which raises some questions. Namely,

• If the book I’m quoting has multiple editions, which one should I cite?
• Do I have to find and cite the latest edition?
• Should I include references for both/all editions that I’ve found?

Whether quoting or paraphrasing, include a reference list entry for only the edition of the book that you’ve actually used. Don’t update the entry to look like you’ve used the latest edition because you can’t be sure, without seeing that edition, whether your quotation or paraphrase is correct. Just cite what you see—the edition of the book that you have in front of you.

However, depending on what you’re writing and why you’re citing the book, you might decide that it is important to find and read the latest edition. If you quote or paraphrase from that edition, then you’ll need a reference list entry for only that edition of the book. You don’t need to cite the earlier edition(s) if you are not paraphrasing or quoting from them.

So, in most cases, you’ll need only one reference list entry: one for the book edition from which you’re quoting or paraphrasing.

In rare cases, you might include multiple reference list entries—one for each edition that you discuss in your work. This might happen, for example, if you are writing a review of a book that compares the latest edition with its previous edition.

In the reference list entry, the edition number is placed in parentheses after the title (but before the period at the end of the title element). Because it is not part of the title, the edition information is not italicized.

You can find more examples in Sections 10.2 and 10.3 of the Publication Manual (7th ed.) and on the reference examples topic page.