Photipim, M. , Ketbumroong, V. , Norkaew, J. , Sungwalee, W. and Chavengkun, W. 2020. The Effect of the Senior Schooling Program to Increase the Happiness Level Among the Elderly Living in Muen Wai Sub-district, Mueang District, Nakhon Ratchasima Province . HCU Journal. 24, 1 (Jun. 2020), 98–106.