Miftahul Khairat, Laura, and Syamsurizal Syamsurizal. “Literature Study: The Effect of Problem-Based Learning Model on Students’ High-Order Thinking Skills (HOTS) in Biology Learning”. Al-Alam: Islamic Natural Science Education Journal, vol. 5, no. 2, July 2026, pp. 655-68, doi:10.33477/al-alam.v5i2.15886.