Itabashi, S., J. Chompikul, B. Keiwkarnka, N. Sowattanangoon, and S. Trakulsri. “Life Satisfaction of the Elderly in Phukhiao District, Chaiyaphum Province, Thailand”. Journal of Public Health and Development, vol. 8, no. 2, Aug. 2010, pp. 123-34, https://he01.tci-thaijo.org/index.php/AIHD-MU/article/view/105499.