Phopum, Natchapapha, Pharapratya Chayawutto (Thinteaw), and Pradit Chuenban. 2019. “A Development of English Communication Skills of the Student in Surin Province by Using CLT Theory”. Journal of Graduate MCU KhonKaen Campus 6 (4):109-22. https://so02.tci-thaijo.org/index.php/jg-mcukk/article/view/227615.