Ibrahim, Sultan, Bambang Raharjo, and Agus Raharjo. “Differences in Interval Training and Fartlek Training Methods on Increasing VO2MAX in Pembalang FC Regency Football Players North Luwu”. Journal of Physical Education and Sports 12, no. 2 (June 30, 2023): 81-87. Accessed December 20, 2024. https://journal.unnes.ac.id/sju/jpes/article/view/78066.