Thommasorn, K., and P. Thaithani. “The Effects of Contemplative Education Activity on Self-esteem of Hotel Employees”. Ratchaphruek Journal, vol. 20, no. 1, Mar. 2022, pp. 27-37, https://so05.tci-thaijo.org/index.php/Ratchaphruekjournal/article/view/252742.