Dwi Novita, Ria, Tien Aminatun, and Rihab Wit Daryono. 2022. “E-Modules Through Flipped Classroom and PBL Models on Environmental Pollution Material to Increase Problem-Solving Ability”. Journal of Education Technology 6 (4):744-54. https://doi.org/10.23887/jet.v6i4.51656.