Phowat, T., S. Nanthamongkolchai, S. Pitikultang, C. Munsawaengsub, and P. Taechaboonsermsak. “Factors Influencing Successful Aging in Pichit Province”. Journal of Health Science of Thailand, vol. 28, no. Supplement 2, Dec. 2019, pp. S6-S15, https://www.thaidj.org/index.php/JHS/article/view/8276.