National Fire Protection Association (Estados Unidos). (1998). National electrical code: NFPA 70 (1999 edition.).
Chicago-viite (17. p.)National Fire Protection Association (Estados Unidos). National Electrical Code: NFPA 70. 1999 edition. Quincy, MA (Batterymarch Park, Quincy 02269) : National Fire Protection Association, 1998.
MLA-viite (9. p.)National Fire Protection Association (Estados Unidos). National Electrical Code: NFPA 70. 1999 edition. 1998.
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