Omer, Elkhalifa Mohamed. “THE ATA SYSTEM: ITS ORIGIN, DEVELOPMENT AND SOCIO-ECONOMIC IMPACT ON THE SOCIETY OF MEDINA DURING THE ERAS OF THE RIGHTLY GUIDED CALIPHS (11-40AH/632-661AD)”. Journal of Al-Tamaddun 15, no. 1 (May 9, 2020): 109–117. Accessed November 24, 2024. https://vmis.um.edu.my/index.php/JAT/article/view/19784.