Sijabat A, . M, . D. EFFECT OF PROBLEM SOLVING LEARNING MODEL AND UNDERSTANDING THE CONCEPT OF PHYSICS STUDENT LEARNING OUTCOMES. JPF Unimed [Internet]. 2016 Dec. 1 [cited 2025 Jul. 3];5(2):87-91. Available from: https://jurnal.unimed.ac.id/2012/index.php/jpf/article/view/4404