S. Bloehdorn, and A. Moschitti. CIKM '07: Proceedings of the sixteenth ACM conference on Conference on information and knowledge management, page 861--864. New York, NY, USA, ACM, (2007)
A. Moschitti, and F. Zanzotto. ICML '07: Proceedings of the 24th international conference on Machine learning, page 649--656. New York, NY, USA, ACM, (2007)