- Taylor & Francis, (2009)
- ICLS 1, page 85-92. International Society of the Learning Sciences, (2008)
- International Journal of Computers for Mathematical Learning 9(3):309--326 (2004)
- the International Journal for Technology in Mathematics Education 13(2):65-78 (2006)
- the 7th International Conference on Technology in Mathematics Teaching, Bristol, (2005)
- Micromath 20(2):17-23 (2004)
- J. Comp. Assisted Learning 22(2):114-136 (2006)
- J. Comp. Assisted Learning 21(2):143-158 (2005)
- The Fourth Conference of the European Society for Research in Mathematics Education CERME 4, page 438 - 447. Spain, (2005)
- Lecture Notes in Computer Science (2006)
- (2004)
- International Journal of Continuing Engineering Education and Life Long Learning 12(5):521-540 (2002)
- AIED, volume 200 of Frontiers in Artificial Intelligence and Applications, page 804. IOS Press, (2009)
- Educational Studies in Mathematics 65(3):367-384 (2007)
- Journal of Education and Work (2006)
- Human Development 52(2):129-147 (2009)
- Cognition and Instruction 13(4):479-482+ (1995)
- Cognition and Instruction 13(c 2002 Inst. For Sci. Info):505-523+ (1995)
- International Journal of Computers for Mathematical Learning 1(1):3-31 (1996)
- British Education Research Journal (1989)


author