Lamphuttha, P. T. “A Study of English Instruction Improvement of Teachers Toward Students of Mathayomsuksa 1-3 Students at Sutepnakornwich School in Roi Et Province”. Journal of MCU Humanities Review, vol. 6, no. 1, July 2020, pp. 165-7, https://so03.tci-thaijo.org/index.php/human/article/view/236644.