Sara Comai Ernesto Damiani Roberto Posenato Letizia Tanca A Schema-Based Approach to Modeling and Querying WWW Data. 110-125 http://link.springer.de/link/service/series/0558/bibs/1495/14950110.htm 1998 conf/fqas/1998 FQAS db/conf/fqas/fqas98.html#ComaiDPT98