Não informado. (1968). Professional Engineer. National Society of Professional Engineers.
Cita Chicago Style (17a ed.)Não informado. Professional Engineer. Jersey City, NJ: National Society of Professional Engineers, 1968.
Cita MLA (8a ed.)Não informado. Professional Engineer. National Society of Professional Engineers, 1968.
Precaución: Estas citas no son 100% exactas.