Syahruddin, S., Y. Manfred Mandosir, I. P. Eka Wijaya Putra, E. Sinaga, and B. Kristanto. “The Effect of Vitamin C Supplementation on Maximum Physical Activity Toward Leucocytes Total”. Jurnal SPORTIF : Jurnal Penelitian Pembelajaran, Vol. 7, no. 1, Apr. 2021, pp. 105-23, doi:10.29407/js_unpgri.v7i1.15715.