Gianni Amati Daniela D. Aloisi Vittorio Giannini Flavio Ubaldini A Framework for Filtering News and Managing Distributed Data. 1007-1021 1997 3 J. UCS 8 db/journals/jucs/jucs3.html#AmatiAGU97 http://www.jucs.org/jucs_3_8/a_framework_for_filtering