Antonia Azzini Stefania Marrara Toward Trust-based Multi-modal User Authentication on the Web: A Fuzzy Approach. 1-6 2007 FUZZ-IEEE http://dx.doi.org/10.1109/FUZZY.2007.4295594 conf/fuzzIEEE/2007 db/conf/fuzzIEEE/fuzzIEEE2007.html#AzziniM07