National Electrical Code 3 : (NEC) A standard for safe electrical installations prepared and revised every three years by a committee of the National Fire Protection Association
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}