Cita APA (7a ed.)

National Electric Light Association. (1931). Underground systems reference book (1a ed.). [s.n.].

Cita Chicago Style (17a ed.)

National Electric Light Association. Underground Systems Reference Book. 1a ed. New York: [s.n.], 1931.

Cita MLA (9a ed.)

National Electric Light Association. Underground Systems Reference Book. 1a ed. [s.n.], 1931.