Atthaprajong, S., and S. Amornpan. “The Strengthen Teacher Competency Program in Classroom Management for School under Secondary Education Service Area Office 20”. Journal of Education Rajabhat Maha Sarakham University, vol. 17, no. 1, Mar. 2020, pp. 519-27, https://so06.tci-thaijo.org/index.php/edu-rmu/article/view/252234.