1. Bigelow, J. C., Davis, G. E., & Hunting, R. P. (April 1989). Some remarks on the homology and dynamics of rational number learning. Paper presented at the Research Pre-session, Annual Meeting of the National Council of Teachers of Mathematics, Orlando Florida.
2. Brown, S. I., & Walter, M. I. (1983). The art of problem posing. Philadelphia: Franklin Institute Press.
3. Carpenter, T. P., Fennema, E., Peterson, P. L., & Carey, D. A. (April 1987). Teachers’ pedagogical content knowledge in mathematics. Paper presented at the Annual Meeting of the American Educational Research Association, Washington D.C.
4. Cobb, P., Yackel, E., & Wood, T. (1988). Curriculum and teacher development: Psychological and anthropological perspectives. In E. Fennema, T. P. Carpenter, & S. J. Lamon (Eds.), Integrating research on teaching and learning mathematics (pp. 92–130 ). Madison WI: Wisconsin Center for Education Research, University of Wisconsin-Madison.
5. Cobb, P., & Steffe, L. P. (1983). The constructivist researcher as teacher and model builder. Journal for Research in Mathematics Education, 14 (2), 83–94.