W. Fresenius, Schneider, W., Boehnke, B., and Poeppinghaus, K.,
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I. N. U. N. I. C. E. F. Reg Delhi and Delhi, I. N. Indian Mar,
“Water, environment and sanitation : report of quantitative phase of knowledge, attitudes and practises study in rural India : phase III”. UNICEF Regional Office for South Central Asia, New Delhi, India, p. 192, xvi p.: fig., tab., 1989.
G. A. Bridger,
Water quality and treatment, vol. no. D3. Ratmalana, Sri Lanka: National Water Supply and Drainage Board, 1989, p. iv, 182 p.: fig., tab.
G. A. Bridger,
Water service connections, vol. no. D-8. Ratmalana, Sri Lanka: National Water Supply and Drainage Board, 1989, p. ii, 93 p.: fig., tab.