1. Antonini, S. (2003). Non-examples and proof by contradiction. In N. Pateman, B. J. Dougherty, & J. Zilliox (Eds.), Proceedings of the 27
th annual meeting of the International Group for Psychology in Mathematics Education (Vol. 2, pp. 49–55). Honolulu: University of Hawaii.
2. Arbib, M. A. (1990). A Piagetian perspective on mathematical construction. Synthese, 84(1), 43–58.
3. Arzarello, F., Olivero, F., Paola, D., & Robutti, O. (2002). A cognitive analysis of dragging practises in Cabri environments. ZDM, 34(3), 66–72.
4. Arzarello, F., & Sabena, C. (2011). Semiotic and theoretic control in argumentation and proof activities. Educational Studies in Mathematics, 77(2–3), 189–206.
5. Baccaglini-Frank, A., & Mariotti, M. A. (2010). Generating conjectures in dynamic geometry: The maintaining dragging model. International Journal of Computers for Mathematical Learning, 15(3), 225–253.