Bookland barcodes are EAN-13 barcodes with number system 978 (hence "Bookland"). The data they encode is an ISBN with its check digit removed. This is a convenience class that takes an ISBN no instead of "pure" EAN-13 data.
Removes any non-digit characters, number system and check digit from ISBN, so "978-82-92526-14-9" would result in "829252614"
[Validate]