1.
Geneva, Switzerland : World Intellectual Property Organization, 1970.
English | E 2316G173113 WIPO.PCT/PCD(F/E |
2.
[Paris] : Flammarion, c1983.
French | K 339 THI.P |
3.
Berlin Et Al : De Gruyter Verlag, 1972.
German | R 26 HOF.W |