A. Esuli, and F. Sebastiani. ISTI-PP-002/2007. Institute of Information Science and Technologies (ISTI) of the Italian National Research Council (CNR), (October 2006)
F. Debole, and F. Sebastiani. Proceedings of LREC-04, 4th International Conference on Language Resources and Evaluation, page 971--974. Lisbon, PT, (2004)
A. Esuli, and F. Sebastiani. Proceedings of the 2005 ACM CIKM International
Conference on Information and Knowledge Management, page 617--624. ACM, (2005)