“The Success of Problem-Based Learning (PBL) Method on the Improvement of TOEFL Preparation Listening Score at UPT Bahasa Universitas Khairun Students Course”. EDU Journal - English Department of UMMU Journal 3, no. 1 (May 21, 2023): 1–7. Accessed November 2, 2025. https://jurnal.ummu.ac.id/index.php/edu/article/view/1570.