- Cognition and Instruction 23(2):237-309 (2005)
- Educational Researcher 34(4):14-22 (2005)
- Proceedings of 21st Conference of PME-NA, page 23-44. Columbus, Ohio, Clearing House for Science, mathematics, and Environmental Education, (2001)
- Mathematical Thinking and Learning 2(3):157-189 (2000)
- Educational Studies in Mathematics 62(2):191-209 (2006)
- Educational Studies in Mathematics 46(1):187-228 (2001)
- Kluwer Academic Publishers, Dordrecht, (2002)


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