Não informado. (1920). Contractors and engineers monthly. Buttenheim-Dix Publishing.
Chicago (17e ed.) BronvermeldingNão informado. Contractors and Engineers Monthly. New York: Buttenheim-Dix Publishing, 1920.
MLA (8e ed.) BronvermeldingNão informado. Contractors and Engineers Monthly. Buttenheim-Dix Publishing, 1920.
Let op: Deze citaties zijn niet altijd 100% accuraat.