Lessons learned from a randomised controlled trial on web learning. - Canegallo, L.; Pinelli, I.; Beccalli, M. G.; Lodi, G.; Bez, C.; Demarosi, F.; Sardella, A.; Esposito, A.; Visioli, S.; Zannini, L.; Carrassi, A. (European Journal of Dental Education, 2003)