Não informado. (1987). UNCTAD commodity yearbook. United Nations.
Style de citation Chicago (17e éd.)Não informado. UNCTAD Commodity Yearbook. New York: United Nations, 1987.
Style de citation MLA (8e éd.)Não informado. UNCTAD Commodity Yearbook. United Nations, 1987.
Attention : ces citations peuvent ne pas être correctes à 100%.