Kitikanan, P., and P. Sasimonton. “The Relationship Between English Self-Efficacy and English Learning Achievement of L2 Thai Learners”. LEARN Journal: Language Education and Acquisition Research Network, vol. 10, no. 1, Dec. 2017, pp. 149-64, https://so04.tci-thaijo.org/index.php/LEARN/article/view/135969.