K. K. Al-Ahmady, D. and S. M. AL-Dabag, E. (2014) “Effect of Recirculation Ratio, Organic Loading and Suspended Solids Loading on the Efficiency of the Trickling FiltersWith Plastic Media”, Al-Rafidain Engineering Journal (AREJ), 22(3), pp. 147–157. doi: 10.33899/rengj.2014.88209.