Nga, T. T., N. T. Hop, and N. T. H. Nga. “The Impact of Feedback and Correction of Students’ Speech Errors on Their Oral Production”. VNU Journal of Foreign Studies, vol. 29, no. 1S, Dec. 2013, pp. 80-89, https://jfs.ulis.vnu.edu.vn/index.php/fs/article/view/5117.