Supapan, A., D. Yaimsang, and P. Srisaard. “Early Childhood Education Management for Thailand 4.0, Private Schools in Maha Sara Kham Province”. Journal of Research and Development Institute Rajabhat Maha Sarakham University, vol. 6, no. 1, June 2019, pp. 289-02, https://so03.tci-thaijo.org/index.php/rdirmu/article/view/211471.