1. Ainley, J. (1996). Purposeful contexts for normal notation in spreadsheet environment. Journal of Mathematics Behavior, 15, 405–422.
2. Baker, J. E., & Sugden, S. J. (2003). Spreadsheets in education: The first 25 years. Spreadsheets in Education, 1(1). Retrieved on March 2007, from http://www.sie.bond.edu.au/
3. Dettori, G., Garuti, R., & Lemut, E. (2001). From arithmetic to algebraic thinking by using a spreadsheet. In R. Sutherland, T. Rojano, A. Bell, & R. Lins (Eds.), Perspectives on school algebra (pp. 191–208). Dordrecht, The Netherlands: Kluwer Academic Publishers.
4. Drouhard, J. P., & Teppo, A. R. (2004). Symbols and language. In K. Stacey, H. Chick, & M. Kendal (Eds.), The future of the teaching and learning of algebra (pp. 227–266). The 12th ICMI study. Dordrecht, The Netherlands: Kluwer Academic Publishers.
5. Filloy, E., & Sutherland, R. (1996). Designing curricula for teaching and learning algebra. In A. J. Bishop, K. Clements, C. Keitel, J. Kilpatrick, & C. Laborde (Eds.), International handbook of mathematics education (pp. 139–160). Dordrecht, The Netherlands: Kluwer Academic Publishers.