Dhuha, A. A., S. Sulaiman, and H. Pramono. “The Effect of Endurance and Leg Muscle Strength Training Method on the Increase of VO2Max”. Journal of Physical Education and Sports, Vol. 8, no. 6, Dec. 2019, pp. 275-80, https://journal.unnes.ac.id/sju/jpes/article/view/36073.