1. Arcavi, A. (1994). Symbol sense: Informal sense-making in formal mathematics. For the Learning of Mathematics, 14(3), 24–35.
2. Banchoff, T. (2008). Algebraic thinking and geometric thinking. In C. E. Greenes, R. Rubenstein (Eds.), Algebra and algebraic thinking in school mathematics, NCTM seventieth yearbook (pp. 99–110). National Council of Teachers of Mathematics
3. Blanton, M., Isler-Baykal, I., Stroud, R., Stephens, A., Knuth, E., & Gardiner, A. (2019). Growth in children’s understanding of generalizing and representing mathematical structure and relationships. Educational Studies in Mathematics, 102(3), 193–219. https://doi.org/10.1007/s10649-019-09894-7
4. Brizuela, B. M., & Earnest, D. (2008). Multiple notational systems and algebraic understandings: The case of the “Best Deal” problem. In J. J. Kaput, D. W. Carraher, & M. L. Blanton (Eds.), Algebra in the early grades (pp. 273–301). Lawrence Erlbaum.
5. Bruner, J. S. (1966). Toward a theory of instruction. Belknap Press.