1. Baliga, G., Case, J., Merkle, W., Stephan, F., & Wiehagen, W. (2008). When unlearning helps. Information and Computation, 206(5), 694–709.
2. Ball, D. L., Lubienski, S., & Mewborn, D. (2001). Research on teaching mathematics: The unsolved problem of teachers’ mathematical knowledge. In V. Richardson (Ed.), Handbook of research on teaching (4th ed., pp. 433–456). New York: Macmillan.
3. Barrows, H. S., & Myers, A. C. (1993). Problem-based learning in secondary schools. Springfield: Problem-Based Learning Institute, Lanipher High School, and Southern Illinois Medical School.
4. Barrows, H. S., & Tamblyn, R. M. (1980). Problem-based learning: An approach to medical education. New York: Springer.
5. Bridges, S., Botelho, M., Green, J., & Chau, A. M. (2012). Multimodality in problem-based learning (PBL): An interactional ethnography. In S. Bridges, C. McGrath, & T. L. Whitehill (Eds.), Problem-based learning in clinical education (Vol. 8, pp. 99–120). The Netherlands: Springer.