Putri, V. N. E., Yudiana, Y., Sidik, D. Z., Nugraha, E. and Jatmiko, T. (2024) “The OPT (Optimum Performance Training) method for 12 weeks increases strength and power of female athletes from the Indonesian National Beach Volleyball Team”, Jurnal SPORTIF : Jurnal Penelitian Pembelajaran, 10(3), pp. 405–419. doi: 10.29407/js_unpgri.v10i3.23200.