Nguyen LC, Ngo NV, Ngoc NTL, Hung MV. Impact of problem-based learning on critical thinking: An exploration with middle school students. ijirss [Internet]. 2025 Apr. 1 [cited 2026 Jan. 22];8(2):2809-1. Available from: http://www.ijirss.com/index.php/ijirss/article/view/5819