Lamp caps and holders together with gauges for the control of interchangeability and safety - Part 1: Lamp caps (IEC 60061-1:1969 + Supplements A:1970 to V:1997 + A21:1998 to A27:2001, modified); German version EN 60061-1:1993 + A1:1995 to A7:1997 + A21:1998 to A27:2001— 267 стр.