Bangko, A. M., Supriadi, A., & Valianto, B. (2020). THE CONTRIBUTION OF BAR TWIST EXERCISES ANDTRAINING ON SIGNAL ACOUSTIC UPPER SERVICE ABILITY IN SEPAK TAKRAW ATHLETES IN NORTH SUMATRA. Indonesia Sport Journal, 3(2), 76–83. https://doi.org/10.24114/isj.v3i2.37826