Biblio

B. Karlin and Visscher, J. T., “Water supply and sanitation in primary school education in developing countries : a preliminary study”, vol. no. 13. IRC, The Hague, The Netherlands, p. 42 p.: fig., 1988.

B. Karlin and Isely, R. B., “Developing and using audio-visual materials in water supply and sanitation programs”, vol. no. 30. Water and Sanitation for Health Project (WASH), Arlington, VA, USA, p. v, 111 p. + 137 p annexes : 6 fig., 3 tab., 1984.