Al-Mayah, W. T., and A. M. Rabee. “Application of Overall Index of Pollution (OIP) for the Evaluating of the Water Quality in Al-Gharraf River Southern of Iraq”. Iraqi Journal of Science, Vol. 59, no. 2A, Apr. 2018, pp. 660-9, https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/319.