ISBNtunnuksen
ISBNtunnuksen is the Finnish term for ISBN, which stands for International Standard Book Number. It is a unique numerical identifier for books. An ISBN is assigned to each edition and variation (such as hardcover, paperback, and audiobook) of a book. The ISBN is not a substitute for a catalog record, but rather a key to that record. The system is managed by the International ISBN Agency, with national agencies responsible for assigning ISBNs within their respective countries. In Finland, the ISBN agency is part of the National Library of Finland.
The ISBN consists of ten or thirteen digits. Originally, it was a ten-digit number, but it was
ISBNs are used by booksellers, libraries, publishers, and other participants in the book industry to identify