- Educational Studies in Mathematics (May 2007)Online first .
- ZDM (June 2007)Online first .
- ZDM (June 2007)Online first .
- ZDM 37(4):287--307 (2005)
- Journal for Research in Mathematics Education 19(2):99-114 (1988)
- ZDM (2007)
- ZDM (2007)
- Educational Research and Evaluation 5(2):85--104 (1999)
- The Journal of Genetic Psychology 167(1):31--45 (2006)
- Journal of Curriculum Studies 31(4):399--427 (1999)
- Comparative Education Review 49(3):311--43 (2005)
- The Elementary School Journal 101(1):3--20 (2000)
- Phi Delta Kappan (1997)
- National Center for Education Statistics, (2003)
- Cape, (1979)
- Cassel, London, (1984)
- Kluwer Academic Publishers, Dordrecht, (1988)
- The Macmillan Company, 866 Third Avenue, New York, NY 10022, (1970)
- European journal of psychology of education 9(2):139--147 (1994)
- Gothenburg, (1987)


user