Prihatin Ningsih Sagala, Eri Widyastuti. Development Of Junior High School Mathematics E-Book And Student Project Sheet Based On Integrated Merdeka Belajar Project Based Learning. IJERSC [Internet]. 2021Dec.25 [cited 2024Nov.19];2(6):1490-50. Available from: https://ijersc.org/index.php/go/article/view/60