Mahdalena Nasution. “PENERAPAN MODEL PEMBELAJARAN PROBLEM BASED LEARNING DALAM MENINGKATKAN HASIL BELAJAR PAI”. Jurnal Siklus: Penelitian Tindakan Kelas (PTK), vol. 1, no. 1, Aug. 2023, pp. 135-47, https://ejournal.edutechjaya.com/index.php/siklus/article/view/133.