TY - BOOK AU - Electricity Training Association,ed TI - Power system protection volume 4 : digital protection and signalling AV - TK3226 P683 PY - 1997/// CY - London PB - Institution of Electrical Engineers KW - ELECTRIC POWER SYSTEMS KW - PROTECTION KW - GREAT BRITAIN KW - ELECTRIC POWER TRANSMISSION KW - EQUIPMENT AND SU ER -