Kossay K. Al-Ahmady, Dr., and Nadia A. Al-Rhmany. “Performance Study of the Single and Double Stages Anaerobic Biological Filters in Treating Domestic Greywater”. Al-Rafidain Engineering Journal (AREJ) 19, no. 5 (October 28, 2011): 10–21. Accessed September 7, 2025. https://jamh.uomosul.edu.iq/index.php/arej/article/view/30822.