ISBN

What is an ISBN?

An ISBN is the best way to find and identify individual books online. Unlike titles or authors, no two books have the same ISBN. If you search for a book by its ISBN, you’re almost guaranteed to find that exact book.

According to ISBN.org,

“The International Standard Book Number (ISBN) is a 10-digit number that uniquely identifies books and book-like products published internationally.”

ISBNs come in 10-digit and 13-digit varieties, though 10-digit ISBNs are gradually being phased out. Some older books do not have ISBNs.

How do I Find a Book’s ISBN?

Many books, including most textbooks, carry their ISBNs on the back cover, just above the bar code.

If you can’t find the ISBN on the back cover, search inside the front of the book, near the bottom of the book’s Copyright Page (sometimes called the Library of Congress page) that lists details of its publication.

Textbooks often have several ISBNs representing different editions: teacher ed., student ed., international ed., and so on. When selling your textbooks, it’s important to locate the correct ISBN for your edition.

When entering ISBNs into a search box, you can almost always leave out the dashes. If you were searching for the book above, you could enter 9781418050269 instead of 978-1-4180-5026-9.

If you need more information, perhaps Wikipedia will be of service.