Azhar Aziz, Endang Haryani, and nurmaida irawani siregar. “Education Psychology and Learning Performance: Does Mental Skills and Mental Techniques Influences Learning Performance? A Survey Study on Indonesian Educational Institutions”. Revista de Psicología del Deporte (Journal of Sport Psychology) 31, no. 1 (March 16, 2022): 26-39. Accessed August 19, 2022. https://rpd-online.com/index.php/rpd/article/view/632.