"Evaluation of Sana’a Wastewater Treatment plant: Problem Analysis and Suggested Results" (2023) Hadhramout University Journal of Natural & Applied Sciences, 16(2). موجود في: https://hu.edu.ye/hu-publications/journals/index.php/hujnas/article/view/180 (تاريخ الوصول: 28 يوليو 2026).