J. Huang, and E. Efthimiadis. Proceeding of the 18th ACM conference on Information and knowledge management, page 77--86. New York, NY, USA, ACM, (2009)
K. Munir, M. Odeh, and R. McClatchey. IDEAS '08: Proceedings of the 2008 international symposium on Database engineering &\#38; applications, page 81--90. New York, NY, USA, ACM, (2008)