Tazijan, F., A. Murugan, S. Abd.Rahim, R. Mohamed, E. J. Mathai, and R. Ismail. “A Survey of Flipped Learning Approach in the ESL Context”. Asian Journal of Education and E-Learning, vol. 4, no. 2, Apr. 2016, https://ajouronline.com/index.php/AJEEL/article/view/3562.