Utami WMP, Nirmala N. INVESTIGATING THE IMPACT OF PROBLEM BASED LEARNING ON THE TENTH GRADE STUDENTS’ SPEAKING SKILL. JIPIS [Internet]. 2024Oct.30 [cited 2025Apr.5];33(2):145-52. Available from: https://ejournal.unis.ac.id/index.php/JIPIS/article/view/7224