Não informado. (2019). Statistical Yearbook. United Nations, Department of International Economic.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Statistical Yearbook. New York: United Nations, Department of International Economic, 2019.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Statistical Yearbook. United Nations, Department of International Economic, 2019.
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