Safar Alyas Michael Al-Saffar, M., & Khalid Saddiq Al-Shaikh-Ali, D. (2008). Riprap Gradation Effect On Local Scour Around Bridge Piers. Al-Rafidain Engineering Journal (AREJ), 16(1), 56–68. https://doi.org/10.33899/rengj.2008.44049