[Best, J.W., 1981. Research in Education, 4th Ed. Prentice-Hall, New Jersey.]Search in Google Scholar
[BLA Health Plan, Forecasting of Health Care Costs in the Next 12 Years. http://www.bangkoklife.com/healthplan/th/knowledge/detail/1?pno=2 Retrieved on 7 October 2018]Search in Google Scholar
[Department of Economic and Social Affairs, Population Division, United Nations. 2017. https://population.un.org/wpp/ Retrieved on 25 November 2018]Search in Google Scholar
[Lyons, A.C., Grable, J.E., and Joo, S., 2018. A cross-country analysis of population aging and financial security, The Journal of the Economics of Ageing, 12, 96-117.10.1016/j.jeoa.2018.03.001]Search in Google Scholar
[(National Statistics Office. 2017). http://www2.nso.go.th/ Retrieved on 15 November, 2018]Search in Google Scholar
[TCU, 2017. Costs of care for elderly persons skyrocket, TCIJ newspaper. https://www.tcijthai.com/news/2017/11/scoop/7501) Retrieved on 15 November, 2018]Search in Google Scholar
