Rahmawati, Nur Ita, and Imas Cintamulya. “Validity of E-Modules Integrated With Game-Based Problem-Based Learning to Improve 21st Century Skills in Biology Learning”. Biosfer: Jurnal Pendidikan Biologi, vol. 18, no. 1, Mar. 2025, pp. 103-14, doi:10.21009/biosferjpb.49262.