WAN ABDULLAH, W. S. Konsep al-Illah wa al-Ma’lul Ikhwan al-Safa’: Satu Analisa Risalah Fi al-’Ilal wa Al-Ma’lulat. Jurnal Usuluddin, [S. l.], v. 2, p. 175–193, 1995. Disponível em: https://ejournal.um.edu.my/index.php/JUD/article/view/2957. Acesso em: 6 may. 2024.