APA (7e ed.) Bronvermelding

Não informado. (1968). Professional Engineer. National Society of Professional Engineers.

Chicago (17e ed.) Bronvermelding

Não informado. Professional Engineer. Jersey City, NJ: National Society of Professional Engineers, 1968.

MLA (8e ed.) Bronvermelding

Não informado. Professional Engineer. National Society of Professional Engineers, 1968.

Let op: Deze citaties zijn niet altijd 100% accuraat.