1.
London [England] : Trade Marks, Patents and Designs Federation, 1971.
English | N 141 GB 41 |
2.
[Heidelberg, Germany] : [Springer], 1985.
Danish | G 9413G4121 DE 34 |
3.
4.
Cologne [Germany] : German Association for the Protection of Intellectual Property (GRUR), 1982.
German | 29 DE |