Prihatin Ningsih Sagala, and Eri Widyastuti. “Development Of Junior High School Mathematics E-Book And Student Project Sheet Based On Integrated Merdeka Belajar Project Based Learning”. International Journal of Educational Research & Social Sciences 2, no. 6 (December 25, 2021): 1490–1500. Accessed October 15, 2025. https://mail.ijersc.org/index.php/go/article/view/60.