SOMPHONG, Suriyan, Wimonmas PRACHAKUL, and Supitr SAMAHITO. 2012. “THE CONSTRUCTION OF A MENTAL TOUGHNESS MEASURE FOR TAEKWONDO ATHLETES”. Journal of Sports Science and Technology 11 (2):260-73. https://he01.tci-thaijo.org/index.php/JSST/article/view/44020.