Roeth A.O.Najoan, Dwi Andriani Pamase, and Mozes Yustus Legi. “Implementation of the Problem-Based Learning (PBL) Model to Improve Mathematics Learning Outcomes of Third-Grade Students”. ARMADA : Jurnal Penelitian Multidisiplin, vol. 4, no. 6, June 2026, pp. 1311-6, doi:10.55681/armada.v4i6.2255.