A. Saffiotti, and M. Broxvall. Proc of the Int Conf on Smart Objects and Ambient Intelligence (sOc-EUSAI), page 275--280. Grenoble, France, (2005)Online at http://www.aass.oru.se/ãsaffio/.
M. Cerulli, E. Chioccariello, and E. Lemut. Proceedings of CERME 4, Fourth Congress of the European Society for Research in Mathematics Education 17 - 21 February 2005 in Sant Feliu de Guíxols, Spain YERME day: 16- 17 February., ERME, (February 2005)