1.
Fitriani F, Nurhuda N, Ina AI. Improving students’ activeness and critical thinking skills through problem based learning. J. Sci. Educ. [nternet]. 2021Sep.25 [cited 2026Oct.19];2(1):19-2. vailable from: https://jse.rezkimedia.org/index.php/jse/article/view/60