Journal of Environmental Engineering D. D. Mara, R. G. A. Feachem. Water- and Excreta-Related Diseases: Unitary Environmental Classification. Journal of Environmental Engineering. 1999 Apr 1; 125(4):334-339. 1999 https://researcherprofiles.org/profile/79296753 D. D. Mara, R. G. A. Feachem