Não informado. (1961). Society of Petroleum Engineers Journal. Society of Petroleum Engineers.
Chicago-referens (17:e uppl.)Não informado. Society of Petroleum Engineers Journal. Dallas, Tex: Society of Petroleum Engineers, 1961.
MLA-referens (8:e uppl.)Não informado. Society of Petroleum Engineers Journal. Society of Petroleum Engineers, 1961.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.