K. S. Al-Hachamee, Eyad, and Hussain A. A. Al-Quraishi. “Penetration Depth Local Effect of Impactors on Concrete Structures”. Journal of Engineering and Sustainable Development, vol. 14, no. 1, Apr. 2010, pp. 114-21, https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1483.