THE EFFECT OF PROBLEM-BASED LEARNING (PBL) MODEL ON THE PROBLEM-SOLVING SKILLS IN SOCIAL SCIENCE IN ELEMENTARY SCHOOL. JPFKIP [Internet]. 2021 Feb. 21 [cited 2025 Dec. 18];10(1):134-43. Available from: https://primary.ejournal.unri.ac.id/index.php/JPFKIP/article/view/720