Lagut Harahap. “Improving Student Learning Outcomes Using the Problem-Based Learning Model in Grade 4 at SDN 1105 Aek Bonban”. Jurnal Profesionalisme Guru, vol. 1, no. 1, Mar. 2025, pp. 40-44, https://journal.maalahliyah.sch.id/index.php/jpg/article/view/150.