APA (7th ed.) Zitazioa

(1968). National Electrical Code 1968: A USA Standard. National Fire Protection Association.

Chicago Style (17th ed.) Zitazioa

National Electrical Code 1968: A USA Standard. Boston: National Fire Protection Association, 1968.

MLA (9th ed.) Zitazioa

National Electrical Code 1968: A USA Standard. National Fire Protection Association, 1968.