United Nations Environment Programme & GEMS Monitoring and Assessment Research Centre. (1991). Environmental data report (3rd ed. 1991/92.). B. Blackwell.
芝加哥风格引文United Nations Environment Programme 与 GEMS Monitoring and Assessment Research Centre. Environmental Data Report. 3rd ed. 1991/92. Oxford, UK ; Cambridge, Mass., USA: B. Blackwell, 1991.
MLA引文United Nations Environment Programme 与 GEMS Monitoring and Assessment Research Centre. Environmental Data Report. 3rd ed. 1991/92. B. Blackwell, 1991.
警告：这些引文格式不一定是100％准确.