Phokion G. Kolaitis, David L. Martin, Madhukar N. Thakur. On the Complexity of the Containment Problem for Conjunctive Queries with Built-in Predicates. In Proceedings of the Seventeenth ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems, June 1-3, 1998, Seattle, Washington. pages 197-204, ACM Press, 1998. [doi]
Abstract is missing.