siagian roy, Nathanael Sitanggang, M. Joharis Lubis. Project-Based Learning Governance on Natural Materials Improving the Creativity of Class VIII Students of SMP Negeri 1 Sigumpar. Ehdj [Internet]. 2022 Sep. 30 [cited 2026 Aug. 1];7(2):77-84. Available from: https://journal2.unusa.ac.id/index.php/EHDJ/article/view/2964