Hashim Mahmood, an, A. Y. Shehab, and R. M. Saleh Al- Obaidi. “Early Prediction Of Toxic Shocks Happening In Activated Sludge Biological Systems”. Al-Rafidain Engineering Journal (AREJ), vol. 18, no. 1, Feb. 2010, pp. 26-35, doi:10.33899/rengj.2010.27970.