S. I. Asa'ad,
« The hafir », vol. Booklet no. 8. Rural Water Corporation, Democratic Republic of the Sudan, Khartoum, Sudan, p. Various paging ; fig. tab., 1969.
H. M. Ellis, Gilbertson, W. E., Jaag, O., Okun, D. A., Shuval, H. I., et Sumner, J.,
Problems in community wastes management, vol. no. 38. Geneva, Switzerland: World Health Organization (WHO), 1969, p. 89 p. : tab.
C. (State). D. US,
« Proceedings of the symposium on water filtration - the state of the art, Los Angeles, May 16, 1969 ». State of California, Department of Public Health, Berkeley, CA, USA, p. ca 125 p., 1969.
D. Warner,
« Rural water supply in East Africa : proceedings of a workshop held at the University College, Dar es Salaam, 17-19 December 1969 », vol. no.11. University of Dar es Salaam, Bureau of Resource Assesssment and Land Use Planning, Dar es Salaam, Tanzania, p. 160 p. : fig. tab., 1969.
U. P. Gibson et Singer, R. D.,
« Small wells manual : a manual of location, design, construction, use and maintenance ». USAID, Washington, DC, USA, p. vi, 156 p. : fig., tab., 1969.