* Original 1980 hardcover edition: 0-394-50208-7
* 1984 paperback edition: 0-446-35373-3
* 2011 paperback edition: 978-0-316-04934-4
* 2019 paperback edition: 978-0-593-12206-5
You can find the ISBN for a specific edition by searching for it on websites like Amazon, Goodreads, or Barnes & Noble.