Kittisuwannakul, T., A. Wangsrikoon, and C. Sutthirat. “The Needs of Competency for Primary Private School Teachers”. Humanities and Social Sciences Journal of Pibulsongkram Rajabhat University, vol. 11, no. 2, Dec. 2017, pp. 48-57, https://so01.tci-thaijo.org/index.php/GraduatePSRU/article/view/106474.