K. Al-Ahmady, K., and Z. A. AL-Shrefy. “Effect of Organic, Nitrogenous and Phosphorus Loads Variation Onthe Removal Efficiency of Organic and Nutrients Pollutants In Duckweed Based Wastewater Stabilization Ponds”. Al-Rafidain Engineering Journal (AREJ), vol. 23, no. 1, Feb. 2015, pp. 12-22, doi:10.33899/rengj.2015.101022.