Srisermbhok, A. “A Comparison Between Highly Motivated Learners and Unmotivated Learners’ Learning Achievement: A Case Study of Business English Majors at Southeast Bangkok College”. LEARN Journal: Language Education and Acquisition Research Network, vol. 10, no. 1, Dec. 2017, pp. 1-13, https://so04.tci-thaijo.org/index.php/LEARN/article/view/135957.