M. Cerulli, A. Chioccariello, und E. Lemut. 5th CERME conference - congress of European Society for Research in Mathematics Education, Larnaca, Cyprus, (2007)
M. Cerulli, A. Chioccariello, und E. Lemut. Proceedings of the Fourth Congress of the European Society for Research in Mathematics Education (CERME 4), Seite 591-600. Sant Feliu de Guíxols, Spain,, (2005)