Kajchamaporn, Worarat, Kittipong Dongsang, Kulyada Somsap, and Thapanawong Mitsungnern. 2013. “Happiness Status and Related Factors: A Characterization of Grade 10-12 Students at Khonkaenwittayayon School, Khon Kaen, Thailand, 2006”. Srinagarind Medical Journal 22 (3):254-60. https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/13147.