Não informado. (1968). Abstracts of Petroleum Substitutes. American Petroleum Institute.
Chicago (17e ed.) BronvermeldingNão informado. Abstracts of Petroleum Substitutes. New York: American Petroleum Institute, 1968.
MLA (8e ed.) BronvermeldingNão informado. Abstracts of Petroleum Substitutes. American Petroleum Institute, 1968.
Let op: Deze citaties zijn niet altijd 100% accuraat.