THE EFFECTIVENESS OF AUDIO VISUAL-ASSISTED PROBLEM BASED LEARNING IN IMPROVING STUDENTS’ COGNITIVE AND PROBLEM SOLVING ABILITIES ON ALTERNATIVE ENERGY MATERIALS. SPEKTRA [Internet]. 2024 Oct. 10 [cited 2025 Nov. 25];10(2):268-79. Available from: https://ojs.unsiq.ac.id/index.php/spektra/article/view/7801