Liliana Ardissono Anna Goy Giovanna Petrone Marino Segnan Pietro Torasso Ubiquitous User Assistance in a Tourist Information Server. 14-23 2002 conf/ah/2002 AH http://link.springer.de/link/service/series/0558/bibs/2347/23470014.htm db/conf/ah/ah2002.html#ArdissonoGPST02