Simbolon NT, Nababan I, Sagala AF. The Implementation of Problem-Based Learning Model to Improve Junior High School Students’ Mathematical Problem-Solving Ability. OJE [Internet]. 2026 Aug. 17 [cited 2026 Sep. 3];5(2):73-81. Available from: https://www.journal.outlinepublisher.com/index.php/OJE/article/view/719