Não informado. (1944). Drilling contractor. American Association of Oilwell Drilling Contractors.
Chicagoスタイル(17版)引用形式Não informado. Drilling Contractor. Dallas, Tex: American Association of Oilwell Drilling Contractors, 1944.
MLA(8版)引用形式Não informado. Drilling Contractor. American Association of Oilwell Drilling Contractors, 1944.
警告: この引用は必ずしも正確ではありません.