Wan Abdullah, W. S. (1995). Konsep al-Illah wa al-Ma’lul Ikhwan al-Safa’: Satu Analisa Risalah Fi al-’Ilal wa Al-Ma’lulat. Jurnal Usuluddin, 2, 175–193. Retrieved from https://jummec.um.edu.my/index.php/JUD/article/view/2957