When a book has no edition number/name present, it is generally a first edition. If you have to cite a specific edition of a book later than the first, you should indicate the new edition in your citation. If the book is a revised edition or an edition that includes substantial new content, include the number, name, or year of the edition and the abbreviation “ed.” in parentheses between the book title and the period that follows it. “Revised edition” should be abbreviated as “Rev. ed.” and “Abridged edition” should be abbreviated as “Abr. ed.” The edition can usually be found on the title page, as well as on the copyright page, along with the edition’s date.