title: Community water supply and sanitation in developing countries, 1970-1990. An evaluation of the levels and trends of services.
mesh_terms: D003906:Developing Countries; D005544:Forecasting; D006801:Humans; D012424:Rural Population; D012499:Sanitation / Q000639:trends*; D013223:Statistics as Topic; D014505:Urban Population; D014881:Water Supply