Situmorang, R.S. et al. 2024. Development of problem-based learning materials on linear programming to facilitate students’ mathematical problem-solving skills. Jurnal Absis: Jurnal Pendidikan Matematika dan Matematika. 7, 1 (Aug. 2024), 1–11. DOI:https://doi.org/10.30606/absis.v7i1.2339.