1. Measuring Attitudes by Unfolding a Likert-Style Questionnaire
2. A hybrid model of problem-based learning;G.Armstrong;The challenge of problem based learning,1992
3. Evaluating the evidence that problem based learners are self-directed learners: a review of the literature;P.Blumberg;Problem–based learning: A research perspective on learning interactions,2000
4. Brady, L. (1987). Curriculum development (2nd ed.). Sydney, Australia: Prentice Hall Pty. Ltd.