Não informado. Natural Resources & Energy. United Nations, Department of Technical Cooperation for Development.
Citação do estilo Chicago (17ª ed.)Não informado. Natural Resources & Energy. New York: United Nations, Department of Technical Cooperation for Development.
Citação MLA (8ª ed.)Não informado. Natural Resources & Energy. United Nations, Department of Technical Cooperation for Development.
警告：这些引文格式不一定是100％准确.