إبراهيم عبد الله ر. (2012). Thee confrontation of the Khalefa Omar Bin Al-kattab ( to be satisfied with Allah ) to the crisis of ( Am Al-ramada ) 18A.H / 639A.D. College of Basic Education Research Journal, 11(4), 339–361. Retrieved from https://moss.uomosul.edu.iq/index.php/berj/article/view/39126