A. Ibrahim, M., R. R. Al-Omari, and M. H. Ibrahim. “Experimental Study to Improve the Shear Stress of Silty- Sandy Soils by Using Urease Producing Bacteria”. American Scientific Research Journal for Engineering, Technology, and Sciences, vol. 41, no. 1, Apr. 2018, pp. 271-7, https://asrjetsjournal.org/index.php/American_Scientific_Journal/article/view/3853.