Não informado. (1987). UNCTAD commodity yearbook. United Nations.
Chicagoスタイル(17版)引用形式Não informado. UNCTAD Commodity Yearbook. New York: United Nations, 1987.
MLA(8版)引用形式Não informado. UNCTAD Commodity Yearbook. United Nations, 1987.
警告: この引用は必ずしも正確ではありません.