D. Stanton, C. O’Malley, K. Ng, M. Fraser, und S. Benford. Designing for change in networked learning environments: proceedings of the International Conference on Computer Support for Collaborative Learning 2003, Seite 293 – 302. (2003)
F. Arzarello, M. Bussi, und O. Robutti. Proceedings of the 28th International Conference of the International Group for the Psychology of Mathematics Education, 4, Seite 89-96. (2004)