N. Dalvi, and D. Suciu. PODS '07: Proceedings of the twenty-sixth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems, page 1--12. New York, NY, USA, ACM Press, (2007)
A. Halevy, M. Franklin, and D. Maier. PODS '06: Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems, page 1--9. New York, NY, USA, ACM Press, (2006)