M. Yerushalmy, und B. Shternberg. Beyond constructivism: A model and modeling perspective on teaching,learning, and problem solving in mathematics education, Lawrence Album, Mahwah, NJ, (in press)
A. Sacristán. Representations and Mathematics Visualization. Working Group Representations and Mathematics Visualization (1998-2002), North American Chapter of the International Group for the Psychology of Mathematics Education, Seite 127-142. (2002)