Não informado. (2019). Statistical Yearbook. United Nations, Department of International Economic.
Chicagoスタイル(17版)引用形式Não informado. Statistical Yearbook. New York: United Nations, Department of International Economic, 2019.
MLA(8版)引用形式Não informado. Statistical Yearbook. United Nations, Department of International Economic, 2019.
警告: この引用は必ずしも正確ではありません.