yarfan medi, Zaki M, Amalia R. Application Of The Problem Based Instruction (PBI) Learning Model To Improve The Mathematical Problem Solving Abilities Of Students At SMP Negeri 12 Langsa. JDM [Internet]. 2023Nov.14 [cited 2026Nov.14];6(02):111-7. Available from: https://ejurnalunsam.id/index.php/JDM/article/view/8623