Since 2007, 13 international standard book number has been used.

For example: ISBN 978-7-5303-0508-9

978 is called EAN. UCC prefix, the product identification code assigned by EAN international is applied to ean organization by ISSN center. The prefix of EAN. The UCCs in China are 978 and 979, and now 978 is used.

7 is the group area code, which is assigned by the International ISSN Center, and China is 7.

5303-0508 is called publisher number and publication serial number, which is assigned by ISSN Center in China. 5303 stands for Beijing Education Publishing House, and 0508 is the key field for order management and editing of books published by the publishing house.

9 stands for check code, and there is a certain algorithm to check the correctness of ISBN.

The specific algorithm is: the odd number of the first 12 bits of ISBN is multiplied by 1, the even number is multiplied by 3, and the sum of the products is divided by 10 to get the remainder, and this remainder is subtracted by 10 to get the value of the parity bit, which should be in the range of 0-9.

It is difficult to find the book number on the Internet, so we need to use a special database.