Bunma, P. ., and V. . U-on. “Causal Factors That Influences Personal Retirement Planning of Private Company Employee in Thailand”. Journal of Humanities and Social Sciences Thonburi University, vol. 16, no. 2, May 2022, pp. 171-83, https://so03.tci-thaijo.org/index.php/trujournal/article/view/252596.