Rugpolmuang, L., C. Akewanlop, S. Benjarassamerote, P. O-chareanrat, P. Mahasitiwat, and A. Asavamongkolkul. “Falling can be a Serious Problem for the Elderly”. Siriraj Medical Journal, vol. 58, no. 7, July 2006, pp. 916-21, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/245855.