Sandi, Y. “PENGARUH LATIHAN CIRCUIT TRAINING TERHADAP VOLUME OKSIGEN MAKSIMAL (VO2 MAKS) TIM SEPAKBOLA NAGARI DURIAN TINGGI KECAMATAN KAPUR IX”. JURNAL STAMINA, Vol. 2, no. 9, Sept. 2019, pp. 178-85, http://stamina.ppj.unp.ac.id/index.php/JST/article/view/365.