What is the International Standard Book Number (ISBN)?
The ISBN is a ten digit number that uniquely identifies a publication worldwide. You can purchase an ISBN number from R.R. Bowker, the US agency licensed to sell these numbers. The cost is $205 for ten ISBN numbers. ISBN numbers are printed on the copyright page as well as above the bar code on softback books. If one is printing both a hard and a soft cover version of a document, an ISBN will be needed for both versions. Click here for the ISBN website.