Safar Alyas Michael Al-Saffar, Manar, and Dr. Khalid Saddiq Al-Shaikh-Ali. 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.