Biblio

D. Adekile y Ball, P., «Training local technicians in borehole drilling», Waterlines, an international journal of water, sanitation and waste, pp. p. 23-25 : 4 photogr., 2 tab., 2006.

P. Ball, «Solutions for reducing borehole costs in rural Africa». Water and Sanitation Program - African Region, Nairobi, Kenya, p. 12 p. : 6 fig., photogr., 1 tab., 2004.

P. Ball, «Solutions vers la reduction du cout des puits d'eau en milieu rural Africain». Water and Sanitation Program - African Region, Nairobi, Kenya, p. 16 p. : 6 fig., photogr., 1 tab., 2004.

P. Ball y Godfrey, S., «Making boreholes work : rehabilitation strategies from Angola», in Towards the millennium development goals - actions for water and environmental sanitation : proceedings of the 29th WEDC conference, Abuja, Nigeria, 2003, Loughborough, UK, 2003, pp. p. 190-192 : 1 fig.

P. Ball, Drilled wells, vol. no. 6. St. Gallen, Switzerland: SKAT (Swiss Centre for Development Cooperation in Technology and Management), 2001, p. 72 p. : 61 fig., photogr., 13 tab.