E. T. U. N. I. C. E. F. - Ad Ababa, Nairobi, K. E. World Bank, y Ababa, E. T. Water Reso,
«First national hand pump workshop : proceedings of a workshop held in Addis Ababa, Ethiopia, December 14, 1989». Water Resources Commission, Addis Ababa, Ethiopia, p. ii, 79, iv p., 1989.