Ngampiriyakorn, G., N. . Thammawiwat, and W. . Kwalamthan. “The Development of Element’s Happiness in Ongkharak Demonstration School, Srinakharinwirot University”. Interdisciplinary Academic and Research Journal, vol. 2, no. 5, Sept. 2022, pp. 461-80, doi:10.14456/iarj.2022.107.