Não informado. (1981). API Abstracts. American Petroleum Institute.
Chicagoスタイル(17版)引用形式Não informado. API Abstracts. New York: American Petroleum Institute, 1981.
MLA(8版)引用形式Não informado. API Abstracts. American Petroleum Institute, 1981.
警告: この引用は必ずしも正確ではありません.