Simple drilling methods-Brief 43

ELSON, B. and SHAW, R. (1999): Simple drilling methods-Brief 43. En: SHOW, R. (editor). Running Water, More Technical Briefs on Health, Water and Sanitation. Nottingham (UK): Water, Engineering and Development Centre (WEDC)/ Intermediate Technology (IT) Publications, pp.41-44. URL [Accessed: 29.08.2018] PDF