Hoang Lam, P. T., and C. A. Nguyen Thi. “The Impacts of Problem-Based Learning on Grammar Knowledge of Grade 11 Students at a High School in Vietnam”. TTU Journal of Science, vol. 1, no. 3, Sept. 2026, pp. 71-79, doi:10.53901/tjs.2026.v01.issue03.art08.