Le, Hong Nhung, Thi Ha Nguyen, Thi Loan Do, Thi Loan Ngo, and Viet Hoai Nam Le. “INVESTIGATING VOCABULARY RETENTION UNDER SPACED AND MASSED LEARNING CONDITIONS IN THE EFL CLASSROOM”. Hong Duc University Journal of Science, no. 7 (n.d.). Accessed September 11, 2026. https://hdujs.edu.vn/index.php/js/article/view/1321.