Biblio

B. J. Lloyd, Clarke, B. A., Crompton, J. L., and Major, I. P., “Cleaning of upflow gravel prefilters in multistage filtration water treatment plants”, in Advances in slow sand and alternative biological filtration, 1996, pp. P. 391-401 : 10 fig., 1 tab.

B. J. Lloyd, Clarke, B. A., Jones, C. J., and Evans, H. L., “Water treatment by multistage filtration utilising gravel prefilters and fabric enhanced slow sand filters”, in Advances in slow sand and alternative biological filtration, 1996, pp. P. 313-326 : 12 fig., 2 tab.

B. J. Lloyd, Visscher, J. T., and G. C., G., “Multi-stage surface water treatment for community water supply in Colombia”, Waterlines, an international journal of water, sanitation and waste, pp. p. 26-29 : 3 fig., 3 tab., photogr., 1992.