Não informado. (2017). Petroleum Engineer. Petroleum Engineer Publications.
Chicago (17e ed.) BronvermeldingNão informado. Petroleum Engineer. Dallas, Tex: Petroleum Engineer Publications, 2017.
MLA (8e ed.) BronvermeldingNão informado. Petroleum Engineer. Petroleum Engineer Publications, 2017.
Let op: Deze citaties zijn niet altijd 100% accuraat.