National Bibliography Number
National Bibliography Number (NBN) is a group of publication identifier systems used by national libraries in countries such as Germany, Italy, Finland, Norway, and Sweden. There is no global standard for the contents of NBNs; instead, they have a country-specific format. NBNs are typically used for documents which do not have a publisher-assigned identifier such as an ISBN. They can be used to identify persistently media that are archived in national libraries, for instance Ph.D. theses.
An NBN in Germany (
de), in Bavaria (
bvb = Bibliotheksverbund Bayern), library number 19 (University Library Munich), pointing to a PhD thesis on heat detection in cattle.