(2011). Keeping track of our changing environment from Rio to Rio + 20 (1992-2012). United Nations Environment Programme.
Čikaški stil citiranjaKeeping Track of Our Changing Environment from Rio to Rio + 20 (1992-2012). Nairobi, Kenya: United Nations Environment Programme, 2011.
MLA način citiranjaKeeping Track of Our Changing Environment from Rio to Rio + 20 (1992-2012). United Nations Environment Programme, 2011.
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