Th. Hamad Al-Tai, Ammar, and Moamen W. Fathel Al-Tak. “Performance Study of Concentrated Circular Channels System (Orbal) for Removing Nutrients from Domestic Wastewater”. Al-Rafidain Engineering Journal (AREJ) 24, no. 2 (December 1, 2019): 65–73. Accessed August 8, 2025. https://ojs.uomosul.edu.iq/index.php/arej/article/view/27247.