Siahaan, Yuni Hariati, Syarifah Nur Siregar, and Atma Murni. 2026. “Implementation of Problem-Based Learning Model to Improve Mathematical Problem-Solving Skills of Grade XI-2 Students of SMAN 19 Pekanbaru”. Jurnal Didactical Mathematics 8 (1):204-22. https://doi.org/10.31949/dm.v8i1.17437.