Lemons, R., and S. Tao-ngoen. “Study of Phetchabun Rajabhat University Second and Third Year Students’ Listening and Speaking Difficulties in English Language”. Journal of Asian Language Teaching and Learning (Online), vol. 5, no. 2, Aug. 2024, pp. 01-12, https://so10.tci-thaijo.org/index.php/jote/article/view/1401.