Garland, J. D. (1981). National electrical code: Reference book (3rd ed.). Prentice-Hall.
Dyfyniad Arddull ChicagoGarland, J. D. National Electrical Code: Reference Book. 3rd ed. Englewood Cliffs, N. J: Prentice-Hall, 1981.
Dyfyniad MLAGarland, J. D. National Electrical Code: Reference Book. 3rd ed. Prentice-Hall, 1981.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.