1. WHO/sanitation: URL: http://www.who.int/topics/sanitation/en/
2. WHO/10 facts on sanitation: URL: http://www.who.int/topics/sanitation/en/
3. WHO/10 facts on sanitation: URL: http://www.who.int/features/factfiles/sanitation/facts/en/index1.html
4. Prüss A, Kay D, Fewtrell L: Estimating the Burden of Disease from Water, Sanitation, and Hygiene at a Global Level. Environ Health Perspect. 2002, 110 (5): 537-542. 10.1289/ehp.02110537.
5. World Health Organization: WHO | Facts and figures: Water, sanitation and hygiene links to health. 2004, URL: http://www.who.int/water_sanitation_health/publications/factsfigures04/en/