German patents abstracts.
Derwent Publications, Ltd.
London : Derwent Publications,
1988-2001.
Issues also carry dates abstracts were issued, 19 Oct 88-
Patents
German patents gazette. Sections P, Q, General/mechanical
German patents abstracts. Sections P, Q, El, General/mechanical/electrical
Derwent world patent abstracts. German patents. Unexamined published applications. PQ, General/mechanical