L. Fewtrell, Pruss-Ustun, A., Bos, R., Gore, F., en Bartram, J.,
Water, sanitation and hygiene : quantifying the health impact at national and local levels in countries with incomplete water supply and sanitation coverage, vol. no. 15. Geneva, Switzerland: World Health Organization (WHO), 2007, p. viii, 71 p. : 5 fig., 12 tab.