Simatupang , N., Nasution, M. I., & Harianto. (2023). Application of Problem-Based Learning Model to Improve Student Learning Outcomes at SD Negeri 081239 Sibolga. Jurnal Pendidikan Profesi Guru, 1(1), 130–137. Retrieved from https://journal.ar-raniry.ac.id/ppg/article/view/6769