Não informado. (1976). Annual Bulletin of Trade in Chemical Products. United Nations, Economic Commission for Europe.
Citação do estilo Chicago (17ª ed.)Não informado. Annual Bulletin of Trade in Chemical Products. New York: United Nations, Economic Commission for Europe, 1976.
Citação MLA (8ª ed.)Não informado. Annual Bulletin of Trade in Chemical Products. United Nations, Economic Commission for Europe, 1976.
警告:这些引文格式不一定是100%准确.