1. Afamasaga-Fuata'i, K.: 1991, Students' Strategies for Solving Contextual Problems on Quadratic Functions, unpublished doctoral dissertation. Cornell University, Ithaca, NY.
2. Behr, M., Lesh, R., Post, T. and Silver, E.: 1983, ‘Rational-number conceptsrs, in R. Lesh and M. Landau (eds.), Acquisition of Mathematics Concepts and Processes, New York, pp. 91–126.
3. Borba, M.: 1993, Students' Understanding of Transformations of Functions Using Multi-Representational Software, unpublished doctoral dissertation, Cornell University, Ithaca, NY.
4. Borba, M. and Confrey, J.: 1992, ‘Transformations of functions using multi-representational software: Visualization and discrete points’, a paper presented at the Sixteenth Annual Meeting of Psychology of Mathematics Education-NA, Durham, p. 149.
5. Boyer, C. B.: 1968, A History of Mathematics, New York.