(2011). Keeping track of our changing environment from Rio to Rio + 20 (1992-2012). United Nations Environment Programme.
Citação norma ChicagoKeeping Track of Our Changing Environment from Rio to Rio + 20 (1992-2012). Nairobi, Kenya: United Nations Environment Programme, 2011.
Citação norma MLAKeeping Track of Our Changing Environment from Rio to Rio + 20 (1992-2012). United Nations Environment Programme, 2011.
Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.