United Nations -New York, NY, US,
Basic facts about the United Nations. New York, NY, USA: United Nations Department of Public Information, 2004, p. xiv, 376 p.
A. Kiss and Shelton, D.,
International environmental law, 3rd ed.rd ed. Ardsley, NY, USA: Transnational Publishers, 2004, p. xvii, 458 p.
Water and Sanitation Program -Washington, DC, US, WSP,
“Report Rapport Informe 2002-2003”. UNDP-World Bank Water and Sanitation Program, Washington, DC, USA, p. 128 p. : 9 boxes, 3 charts, 3 fig., 60 photogr., 2004.