Não informado. (1961). Society of Petroleum Engineers Journal. Society of Petroleum Engineers.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Society of Petroleum Engineers Journal. Dallas, Tex: Society of Petroleum Engineers, 1961.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Society of Petroleum Engineers Journal. Society of Petroleum Engineers, 1961.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.