Herfiantoro, A., H. Setyawati, and S. Soekardi. “The Effect of Imagery Exercises and Emotional Quotient on the Athletes’ Anxiety Level”. Journal of Physical Education and Sports, Vol. 8, no. 2, Jan. 2019, pp. 153-9, https://journal.unnes.ac.id/sju/jpes/article/view/28072.