Media type: E-Article Title: Computational Logic: Logic Programming and Beyond: Key Constraints and Monotonic Aggregates in Deductive Databases Contributor: Zaniolo, Carlo imprint: Springer Berlin Heidelberg, 2002 Published in: Computational Logic: Logic Programming and Beyond Language: Not determined DOI: 10.1007/3-540-45632-5_5 ISSN: 0302-9743 Origination: Footnote: