Darmawan, Aditya Tito Aji. “Mental Toughness and Self-Confidence of Volleyball Extracurricular Participants: Un Estudio De Las Diferencias De género”. Retos 62 (January 1, 2025): 470–479. Accessed June 10, 2026. https://www.revistaretos.org/index.php/retos/article/view/110600.