International classification of patents for invention under the European Convention of 19th December 1954 :
International classification of patents for invention under the European Convention of 19th December 1954 : Vol. 1: A-B : Vol. 2: C-E , Vol 3: F-H
- Losebl.-Ausg.
14.832
Internationale Patentklassifikation
14.832
Internationale Patentklassifikation