Marisi Sihombing, Siti Masitoh, and Andi Mariono. “Effect Of Direct -Problem Based Learning On Critical Thinking In IBDP Students: -”. Educational Administration: Theory and Practice 29, no. 4 (December 1, 2023): 3274–3279. Accessed September 26, 2025. https://www.kuey.net/index.php/kuey/article/view/7555.