British patents abstracts.
Derwent Publications, Ltd.
London : Derwent Publications, Ltd.,
1980-1982.
Issues also carry dates the abstracts were issued: 11 June 1980-6 Jan. 1982.
Patents
British patents abstracts. Sections P, Q, R, General/mechanical/electrical
British patents abstracts. Section El, Electrical
British patents abstracts. Sections P, Q, General/mechanical