Berliana, A., S. Junaidi, and D. W. Kusuma. “The Relationship Between Mental Toughness and Sports Motivation With The Achievements of Introvert and Extrovert Personality Athletes in Individual Sports”. Journal of Physical Education and Sports, Vol. 12, no. 2, June 2023, pp. 88-98, doi:10.15294/jpes.v12i2.77893.