Fadhlani, Khairul Fahmi, Sanusi Hasibuan, Ibrahim Sembiring, and Indra Kasih. “Development of a Reaction Light Tool for Smash Targets in Volleyball”. Randwick International of Education and Linguistics Science Journal 3, no. 4 (December 31, 2022): 668-674. Accessed May 10, 2026. https://www.randwickresearch.com/index.php/rielsj/article/view/610.