Welni, Efrida, A Fauzi, and Usmeldi Usmeldi. “The Development of Problem Based Learning Device for Junior High School Natural Science Class for Learning Substance Pressure and Its Daily Use Material”. International Journal of Educational Dynamics 2, no. 1 (January 17, 2020): 199-208. Accessed November 21, 2024. http://ijeds.ppj.unp.ac.id/index.php/IJEDS/article/view/246.