gunjina, mingkwan. 2019. “The Factors That Were Related to students’ Happiness Level of Bachelor Degree Students at Rajamangala University of Techology Lanna Chiangmai”. RMUTL Journal of Business Administration and Liberal Arts 7 (2):73-84. https://so05.tci-thaijo.org/index.php/balajhss/article/view/193822.