Adam, Sutisno, and Sulmi Magfirah. “Implementation of Problem-Based Learning Model in TOEFL Preparation Program at Khairun University”. ELS Journal on Interdisciplinary Studies in Humanities 4, no. 4 (December 8, 2021): 424-430. Accessed November 22, 2024. https://journal-old.unhas.ac.id/index.php/jish/article/view/18611.