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International Standard Book Number


The ISBN consists of ten digits and is divided into four parts.

•  Group identifier (language/country of origin)

•  Publisher identifier

•  Title identifier (The book number)

•  Check digit


To calculate the check digit, multiply the last digit of the number by 2, the next to last by 3 etc. and add the results. Minus this number from the next multiple of 11 (11, 22, 33...) to get the check digit.


The ISBN is used for many things like

•  indicating a certain book

•  accounting

•  sales data monitoring

•  ordering / teleordering

•  accounting and billing

•  bibliographic searches

•  ordering

•  information retrieval

•  circulation

•  the national bibliography