Ridwan, M., E. M. Zhuka, A. Haqiyah, and J. Zakaria. “Effectiveness of Interval Training in Increasing Cardiorespiratory Endurance: A Systematic Review”. Physical Education Theory and Methodology, vol. 24, no. 6, Dec. 2024, pp. 1007-14, doi:10.17309/tmfv.2024.6.19.