Salvatore Garruzzo Stefano Modafferi Domenico Rosaci Domenico Ursino An XML-based agent model for supporting user activities on the Web. 181-207 2006 4 Web Intelligence and Agent Systems 2 http://iospress.metapress.com/openurl.asp?genre=article&issn=1570-1263&volume=4&issue=2&spage=181 db/journals/wias/wias4.html#GarruzzoMRU06