M. Yaqoob, W. ., F. . H. Rahil, and M. . A. Al-Neami. “Characteristics of Artificial, Gypsified and Natural Gypseous Soils under Dry Condition”. Engineering and Technology Journal, vol. 37, no. 8A, Aug. 2019, pp. 302-1, http://engtechjournal.org/index.php/et/article/view/525.