Não informado. (2001). Western oil and refining. Palmer Publications.
Chicago (17e ed.) BronvermeldingNão informado. Western Oil and Refining. Los Angeles, Calif: Palmer Publications, 2001.
MLA (8e ed.) BronvermeldingNão informado. Western Oil and Refining. Palmer Publications, 2001.
Let op: Deze citaties zijn niet altijd 100% accuraat.