Somnil, Poosanapas, Wirasak Singhkham, and Peerapong Hadda. 2019. “A SURVEY AND PERCEPTION STUDY ON THE USE OF OUTDOOR FITNESS EQUIPMENT IN PUBLIC PARKS THAT AFFECT THE EXERCISE OF USER”. Journal of Sports Science and Health 20 (3). Bangkok, Thailand:96-109. https://he02.tci-thaijo.org/index.php/spsc_journal/article/view/240424.