R. Talebi, H. Reza Taheri, and M. Sohrabi, “Index of difficulty which is an Effective Factor on especial Skill Formation in Basketball Free Throw: Index of learning difficulty hypothesis”, Rev. Publicando, vol. 5, no. 16 (2), pp. 50–62, Oct. 2018, Accessed: Jan. 22, 2025. [Online]. Available: https://revistapublicando.org/revista/index.php/crv/article/view/1647