KARTAMIHARJA, M. R.; SOPANDI, W.; ANGGRAENI, D. Implementation of Problem-Based Learning (PBL) Approach in Chemistry Instructional with Context of Tofu Liquid Waste Treatment. International Journal of Learning, Teaching and Educational Research, [S. l.], v. 19, n. 5, p. 47–77, 2020. Disponível em: https://ijlter.net/index.php/ijlter/article/view/331. Acesso em: 16 may. 2026.