Sucilawati, S. “The Concept of Shura in Islamic Governance Practice of Shura During the Caliph Umar Bin Khattab”. The International Journal of Politics and Sociology Research, vol. 8, no. 1, June 2020, pp. 19-32, https://www.ijobsor.pelnus.ac.id/index.php/ijopsor/article/view/29.