Sari Aritonang, Tri, and Suhandi Astuti. “The Effectiveness of Discovery Learning and PBL Models on Student’s Critical Thinking Skills”. Musamus Journal of Primary Education 3, no. 2 (April 20, 2021): 157-165. Accessed October 28, 2021. http://ejournal.unmus.ac.id/index.php/primary/article/view/3502.