TY  - BOOK
AU  - BIS
TI  - IS: 3231 - Part 3 - Section - 4 - 1987; Specification forElectrical Relays for Power systems protection Part 3; Requirements for Particular Group of Relays Section 4; Directional Relays and power relays
PY  - 1987///
CY  - New Delhi
PB  - BIS
ER  -