IEC 60061-1:1969 Lamp caps and holders together with gauges for the control of interchangeability and safety. Part 1 : Lamp caps
IEC 60061-2:1969 Lamp caps and holders together with gauges for the control of interchangeability and safety. Part 2 : Lampholders
IEC 60061-3:1969 Lamp caps and holders together with gauges for the control of interchangeability and safety. Part 3 : Gauges
IEC 60061-4:1990 Lamp caps and holders together with gauges for the control of interchangeability and safety; part 4: guidelines and general information