Ermelinda Oro Massimo Ruffolo Towards a System for Ontology-Based Information Extraction from PDF Documents. 1482-1499 2008 OTM Conferences (2) http://dx.doi.org/10.1007/978-3-540-88873-4_38 conf/otm/2008-2 db/conf/otm/otm2008-2.html#OroR08