1. Arzarello, F., Olivero, F., Paola, D., & Robutti, O. (2008). The transition to formal proof in geometry. In P. Boero (Ed.), Theorems in schools: From history, epistemology and cognition to classroom practices (pp. 307–424). Rotterdam: Sense Publishers.
2. Battista, M. T. (2007). The development of geometric and spatial thinking. In F. Lester (Ed.), Second handbook of research on mathematics teaching and learning (Vol. 2, pp. 843–908). Charlotte: Information Age Publishing.
3. Chinnappan, M. (1998a). Schemas and mental models in geometry problem solving. Educational Studies in Mathematics, 36, 201–217.
4. Chinnappan, M. (1998b). The accessing of geometry schemas by high school students. Mathematics Education Research Journal, 10(2), 27–45.
5. Chinnappan, M., & Lawson, M. (2005). A framework for analysis of teachers’ geometric content knowledge and geometric knowledge for teaching. Journal of Mathematics Teacher Education, 8, 197–221.
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