คำวิเศษณ์ บุญพา. “The English Instructional Materials Development on Cultures of ASEAN Countries for Tourist Guides”. Journal of Humanities and Social Sciences, Rajapruk University 1, no. 1 (May 31, 2015): 31–42. Accessed May 4, 2024. https://so03.tci-thaijo.org/index.php/rpu/article/view/112148.