Ananda, Della Widya, Kartini, and Nahor Murani Hutapea. “Implementation of Problem Based Learning Model at Class VII9 of SMP Negeri 21 Pekanbaru”. Journal of Education and Learning Mathematics Research (JELMaR) 1, no. 2 (November 19, 2020): 74–84. Accessed August 25, 2026. https://jelmar.wisnuwardhana.ac.id/index.php/jelmar/article/view/74.