Tyas L, Harjana H, Wahyuningsih D. Need Analysis for the Development of STEM-PjBL Physics Teaching Materials to Improve Students’ Problem Solving Ability in the 21st Century. ijels [Internet]. 2021 Mar. 1 [cited 2024 Jul. 22];6(1). Available from: https://journal-repository.com/index.php/ijels/article/view/3235