Frederico Luiz Gonçalves de Freitas Heiner Stuckenschmidt Andreia Malucelli Helena Sofia Pinto Ontologies and their Applications. 1801-1804 2007 13 J. UCS 12 http://www.jucs.org/jucs_13_12/ontologies_and_their_applications db/journals/jucs/jucs13.html#FreitasSMP07