T. V. Dang, T. G. B. Phung, D. M. Vu, and T. T. T. Nguyen, “The Application of Problem-Based Learning in Soft Skills Courses: An Experiment in Classes with Multidisciplinary Students in Vietnam”, Int. J. Eng. Ped., vol. 15, no. 5, pp. pp. 20–41, Jul. 2025.