Musva, Nurul Lestari, Maria Erna, and Abdullah Abdullah. “The Effectiveness of Problem-Based Flipped Classroom Model in Improving Chemistry Learning Outcomes of Buffer Solution”. Hydrogen: Jurnal Kependidikan Kimia 11, no. 1 (February 15, 2023): 34–39. Accessed August 16, 2025. https://e-journal3.undikma.ac.id/index.php/hydrogen/article/view/6213.