D. Santos, N. Seco, N. Cardoso, and R. Vilela. Proceedings of the 5th International Conference on Language Resources and Evaluation, LREC 2006, page 1986--1991. Genoa, Italy, ELRA, (22--28 May 2006)
J. Nothman, T. Murphy, and J. Curran. EACL '09: Proceedings of the 12th Conference of the European Chapter of the Association for Computational Linguistics, page 612--620. Morristown, NJ, USA, Association for Computational Linguistics, (2009)
S. Sekine, K. Sudo, and C. Nobata. Proceedings of $3^rd$ International Conference on Language Resources and Evaluation (LREC'02), page 1818--1824. Canary Islands, Spain, (May 2002)