Kistener, S., Burns B., Vollmeyer R., & Kortenkamp U.  (2013).  An Explorative Study of Search of Model Space in Problem Solving.   

Trgalova, J., Kortenkamp U., Jahn A P., Libbrecht P., Mercat C., Recio T., et al.  (2011).  I2Geo.net ? a platform for sharing dynamic geometry resources all over Europe.   

Kortenkamp, U.  (2008).  Math Unit Testing ? A New Approach to the Use of Technology in Teaching.  (Laborde, C., Ed.).