1. World Resources Institute (WRI), Projected annual renewable water supply per person by river basin, 2025, WRI, Washington DC, USA, 2000 [http://earthtrends.wri.org/maps_spatial/maps_detail_static.php?map_select=265&theme=2 (accessed 17 November 2008)].
2. World Meteorological Organization (WMO), Comprehensive Assessment of the Freshwater Resources of the World, WMO and Stockholm Environment Institute, Stockholm, Sweden, 1997.
3. Urban agriculture for sustainable cities: using wastes and idle land and water bodies as resources
4. European Commission (EC), Proposal for a Directive of the European Parliament and of the Council on environmental quality standards in the field of water policy and amending Directive 2000/60/EC, COM(2006) 397 final, EC, Brussels, Belgium, 2006.