Abdulrahman Hussin , Darstan. “Cyclical Comparison of Succession of Civilizations by Ibn Khaldun and Spingler”. Journal of University of Raparin 11, no. 2 (July 9, 2024): 874–891. Accessed November 9, 2024. https://journal.raparinuni2024.org/index.php/JUR/article/view/1258.