1. Bruner, J. S., Goodnow, J., & Austin, G. A. (1986). A study of thinking. New Brunswick, NJ: Transaction Publishers.
2. Chunxia, Q., Wang, R., Mok, I. A. C., & Huang, D. (2017). Teaching proposition based on variation principles: A case of teaching formula of perfect square trinomials. In R. Huang & Y. Li (Eds.), Teaching and learning mathematics through variations. [Chapter 7 in this book]
3. Clarke, D. (2000). The learner’s perspective study. In D. Clarke, C. Keitel, & Y. Shimizu (Eds.), Mathematics classrooms in twelve countries: The insider’s perspective (pp. 1–14). Rotterdam: Sense Publishers.
4. Ding, L., Jones, K., & Sikko, S. A. (2017). An expert teacher’s use of teaching with variation to support a junior mathematics teacher’s professional learning in Shanghai. In R. Huang & Y. Li (Eds.), Teaching and learning mathematics through variations. [Chapter 12 in this book]
5. Fodor, J. (1980). On the impossibility of acquiring “more powerful” structures. In M. Piatelli-Palmarini (Ed.), Language and learning: The debate between Jean Piaget and Noam Chomsky (pp. 142–162). London: Routledge.