Media type: E-Article Title: Flexible Query Answering Systems: On Querying Ontologies and Databases Contributor: Bulskov, Henrik; Knappe, Rasmus; Andreasen, Troels imprint: Springer Berlin Heidelberg, 2004 Published in: Flexible Query Answering Systems (2004), Seite 191-202 Language: Not determined DOI: 10.1007/978-3-540-25957-2_16 ISSN: 0302-9743; 1611-3349 Origination: Footnote: