Zeraebruk, Kahsay Negusse, et al. “Assessment of Level and Quality of Water Supply Service Delivery for Development of Decision Support Tools: Case Study Asmara Water Supply”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 14, no. 1, Feb. 2014, pp. 93-107, https://gssrr.org/JournalOfBasicAndApplied/article/view/1341.