SOMMAPEE, Y., O. TUNGTHONGCHAI, and J. JEARRANAI. “A CONSTRUCTION OF FRONT CRAWL STROKE SKILLS RATING SCALES FOR PRATHOMSUKSA 4 STUDENTS OF WATTANA WITTAYA ACADEMY”. Journal of Sports Science and Technology, vol. 15, no. 2, Dec. 2015, pp. 91-100, https://he01.tci-thaijo.org/index.php/JSST/article/view/44938.