ภูเลี่ยมคำณัฐทิตา, วรคำไพศาล, and จันทชุมณัฏฐชัย. “The Development of Listening and Speaking Skills in English for the 3rd Year of Vocation Certificate Students at Northeastern Vocational Institute of Agricultural”. Journal of Roi Et Rajabhat University 13, no. 1 (April 29, 2019): 162-173. Accessed October 15, 2019. https://www.tci-thaijo.org/index.php/reru/article/view/186034.