Sukwong, Thanatpong, Sonthaya Sriramatr, and Dittachai Chankuna. 2021. “Factors Affecting Exercise Behavior and Fat Mass to Fat-Free Mass Ratio of the Personal Trainers”. Journal of Behavioral Science for Development 13 (1):61-79. https://so02.tci-thaijo.org/index.php/JBSD/article/view/242781.