1. Anderson, E. D., & Nelson, J. (1994). An introduction to the concept of slope. Mathematics Teacher, 87, 27–30, 37–41.
2. Halves, pieces, and twoths: constructing and using representational contexts in teaching fractions;Ball,1993
3. The interpretation of graphs representing situations;Bell;For the Learning of Mathematics,1981
4. Becoming a mathematics teacher;Brown,1992
5. Mathematics teacher education;Brown,1990