Luemongkol, R. “THE CAUSAL RELATIONSHIP MODEL OF LEARNING STRESS AMONG HIGH SCHOOL STUDENTS IN ONLINE CLASSES DURING THE COVID-19 OUTBREAK IN MUANGPHAYALAE WITTAYA SCHOOL, CHAIYAPHUM PROVINCE”. Journal of Graduate MCU KhonKaen Campus, vol. 8, no. 2, June 2021, pp. 117-29, https://so02.tci-thaijo.org/index.php/jg-mcukk/article/view/247631.