Kerans, Geterudis, and Khristoforus Palli Ngongo. “Development of Integrated Science Learning through Lesson Studies Using A Problem-Based Learning Model”. International Conference on Elementary Education 3, no. 1 (April 12, 2021): 89-99. Accessed July 10, 2025. https://proceedings2.upi.edu/index.php/icee/article/view/1448.