“THE EFFECT OF PROBLEM BASED LEARNING ON STUDENTS’ SCIENCE LEARNING ACHIEVEMENT AT GRADE IV ELEMENTARY SCHOOLS”. Primary: Jurnal Pendidikan Guru Sekolah Dasar 10, no. 1 (February 16, 2021): 1–7. Accessed December 17, 2025. https://primary.ejournal.unri.ac.id/index.php/JPFKIP/article/view/665.