Awaluddin, A., S. Samsudin, W. Puspitorini, W. Widiastuti, and S. Syahruddin. “A Comprehensive Approach to Enhancing Volleyball Skills: The Role of Problem-Based Learning, Constraint-Led Approach, and Motivation”. Physical Education Theory and Methodology, vol. 25, no. 3, May 2025, pp. 548-55, doi:10.17309/tmfv.2025.3.10.