1. AAMI American National Standard Safe Current Limits for Electromedical Apparatus. (ANSI/AAMI ES1-1993). Arlington Va: Association for the Advancement of Medical Instrumentation; 1993.
2. Health care facilities Article 517 National Electrical Code. 1971;70-333-70-351.
3. Safe use of electricity in hospitals 1971. NFPA 76 BM. Article 30424. National Fire Protection Association. 1971;33.
4. Standard for safety medical and dental equipment. Chicago Ill: Underwriters’ Laboratories Inc. UL 544. May 30 1972; paragraphs 265-275.