simangunsong, ita pratiwi, Napitupulu, E., Lubis, A. and simangunsong, ika trisni 2024. E-Module for Problem-Based Learning Integrating Batak Toba Culture (PBL BTC) to Improve Problem-Solving Ability. Vygotsky: Jurnal Pendidikan Matematika dan Matematika. 6, 2 (Aug. 2024), 119–130. DOI:https://doi.org/10.30736/voj.v6i2.1038.