Não informado. (2017). The Petroleum Engineer. Petroleum Engineer Publishing.
Chicago-Zitierstil (17. Ausg.)Não informado. The Petroleum Engineer. Dallas, Tex: Petroleum Engineer Publishing, 2017.
MLA-Zitierstil (8. Ausg.)Não informado. The Petroleum Engineer. Petroleum Engineer Publishing, 2017.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.