Purba, Windi Sahayani, and Agus Kembaren. “Development of Discovery Learning-Based Chemistry Learning E-Modules on Atomic Structure Materials to Improve Learning Outcomes of Class X Students”. Hydrogen: Jurnal Kependidikan Kimia 14, no. 4 (August 31, 2026). Accessed September 8, 2026. https://e-journal.undikma.ac.id/index.php/hydrogen/article/view/21885.