L. Antova, C. Koch, and D. Olteanu. SIGMOD '07: Proceedings of the 2007 ACM SIGMOD international conference on Management of data, page 713--724. New York, NY, USA, ACM Press, (2007)
J. Spiegel, and N. Polyzotis. SIGMOD '06: Proceedings of the 2006 ACM SIGMOD international conference on Management of data, page 205--216. New York, NY, USA, ACM Press, (2006)
X. Dong, and A. Halevy. SIGMOD '07: Proceedings of the 2007 ACM SIGMOD international conference on Management of data, page 43--54. New York, NY, USA, ACM Press, (2007)
G. Das, V. Hristidis, N. Kapoor, and S. Sudarshan. SIGMOD '06: Proceedings of the 2006 ACM SIGMOD international conference on Management of data, page 395--406. New York, NY, USA, ACM Press, (2006)