Kimei, B. M., S. C. Chhabra, and G. Nyagah. “Dissolved Organic Carbon (DOC) and Coliform Bacteria in Underground Waters in Areas Around Nairobi”. African Journal of Health Sciences, vol. 11, no. 1, Feb. 2005, pp. 61-66, doi:10.4314/ajhs.v11i1.30779.