Sopyan, Muhammad, Bambang Budi Raharjo, and Donny Wira Yudha Kusuma. “The Effect Of High-Intensity Interval Training And Fartlek On Vo2max Players U15 And U23 Pamoso Football School”. JUARA : Jurnal Olahraga 8, no. 1 (April 8, 2023): 556-568. Accessed July 3, 2024. http://jurnal.upmk.ac.id/index.php/juara/article/view/2813.