Phudamrong, Phichet. “ehavior and arketing ix of elective the nnual asic ealthcare ervices ith rivate ompany in the entral egion rea”. Journal of Management Science Nakhon Pathom Rajabhat University 4, no. 1 (November 27, 2018): 33-46. ccessed November 30, 2021. https://so03.tci-thaijo.org/index.php/JMSNPRU/article/view/157333.