Abdallah, M. N. “Wastewater Operation and Maintenance in Egypt (Specific Challenges and Current Responses)”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 18, no. 2, Nov. 2014, pp. 125-42, https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/3150.