E. Tilley, Ulrich, L., Lüthi, C., Reymond, P., and Zurbrugg, C.,
“Compendium of sanitation systems and technologies 2nd edition”, Eawag – Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland, 2014.
R. E. S. Bain, Cronk, R., Wright, J., Yang, J., Slaymaker, T., and Bartram, J.,
“Fecal contamination of drinking-water in low- and middle-income countries: a systematic review and meta-analysis”, vol. 11, no. 5, pp. 23 p.,1 Box., 4 fig., 4 tab., 15-22 Ref., 2014.