Noman, Bilal Jabbar, Safaa H. Abd-Awn, and Hassan O. Abbas. “Effect of Pile Spacing on Group Efficiency in Gypseous Soil”. Civil Engineering Journal 5, no. 2 (February 26, 2019): 373–389. Accessed January 22, 2026. https://civilejournal.org/index.php/cej/article/view/1409.