<Tr> <Th> Website </Th> <Td> www.isbn-international.org </Td> </Tr> <P> The International Standard Book Number (ISBN) is a unique numeric commercial book identifier . Publishers purchase ISBNs from an affiliate of the International ISBN Agency . </P> <P> An ISBN is assigned to each edition and variation (except reprintings) of a book . For example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN . The ISBN is 13 digits long if assigned on or after 1 January 2007, and 10 digits long if assigned before 2007 . The method of assigning an ISBN is nation - based and varies from country to country, often depending on how large the publishing industry is within a country . </P> <P> The initial ISBN configuration of recognition was generated in 1967 based upon the 9 - digit Standard Book Numbering (SBN) created in 1966 . The 10 - digit ISBN format was developed by the International Organization for Standardization (ISO) and was published in 1970 as international standard ISO 2108 (the SBN code can be converted to a ten digit ISBN by prefixing it with a zero). </P>

Can the same book have different isbn numbers