Yamkgathok, N., T. . Siriwong, S. . Thungwa, and L. . Thungwha. “Happiness at Work Affects the Performance of Educational Personnel in Secondary Schools, District 1 in Bangkok”. Journal of Modern Learning Development, vol. 7, no. 9, Oct. 2022, pp. 341-56, https://so06.tci-thaijo.org/index.php/jomld/article/view/257391.