Cite
HARVARD Citation
Institution,, B. (1978) Specification for control switches (switching devices, including contactor relays, for control and auxiliary circuits, for voltages up to and including 1000 V a.c. and 1200 V d.c.).. [Online]. London : British Standards Institution. Available from: http://access.bl.uk/ark:/81055/vdc_100104956078.0x000001