“The Influence of The Problem-Based Learning (PBL) Model on The Learning Outcomes of Fourth Grade Students in Social Studies at SD N 040457 Berastagi”.
Journal of Pedagogi 1, no. 5 (October 26, 2024): 31–36. Accessed April 8, 2025.
https://nawalaeducation.com/index.php/JOP/article/view/702.