Não informado. (2017). The Petroleum Engineer. Petroleum Engineer Publishing.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. The Petroleum Engineer. Dallas, Tex: Petroleum Engineer Publishing, 2017.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. The Petroleum Engineer. Petroleum Engineer Publishing, 2017.
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