Poudel, R. C., D. R. Joshi, N. R. Dhakal, and A. B. Karki. “Anaerobic Digestion of Sewage Sludge Mixture for the Reduction of Indicator and Pathogenic Microorganisms”. Scientific World, vol. 8, no. 8, Oct. 2010, pp. 47-50, doi:10.3126/sw.v8i8.3848.