Não informado. (2017). The Petroleum Engineer. Petroleum Engineer Publishing.
Chicago-referens (17:e uppl.)Não informado. The Petroleum Engineer. Dallas, Tex: Petroleum Engineer Publishing, 2017.
MLA-referens (8:e uppl.)Não informado. The Petroleum Engineer. Petroleum Engineer Publishing, 2017.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.