M. Deodhar, and J. Ghosh. Proceedings of the 15th ACM SIGKDD international conference on Knowledge discovery and data mining, page 249--258. New York, NY, USA, ACM, (2009)
D. Agarwal, and S. Merugu. Proceedings of the 13th ACM SIGKDD international conference on Knowledge discovery and data mining, page 26--35. New York, NY, USA, ACM, (2007)