Khunsaard, P., and K. Kruajak. “Participatory Process of Exercise Program for Elderly, Ban Hong Hae Village, Mae Rai Sub-District, Mae Chan District, Chiang Rai Province”. Journal of Health Science of Thailand, vol. 28, no. S2, Dec. 2019, pp. S16-S22, https://thaidj.org/index.php/JHS/article/view/8278.