Ugo Galassi Marco Botta Attilio Giordana Hierarchical Hidden Markov Models for User/Process Profile Learning. 487-505 2007 78 Fundam. Inform. 4 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=78&issue=4&spage=478 db/journals/fuin/fuin78.html#GalassiBG07