Saputra, M. Pd HY, Simanjuntak, MA I. Sisitem Penggantian Kepala Negara, Khilifah, Amir Al-Mu’minin dan Imam Masa Abu Bakar As-Shiddiq dan Umar Bin Khattab. JABSHAR [Internet]. 2024 Jul. 20 [cited 2025 Dec. 17];4:1-7. Available from: https://www.ojs.staisamora.ac.id/index.php/samora/article/view/68