S. Bloehdorn, and A. Hotho. Proceedings of the MSW 2004 workshop at the 10th ACM SIGKDD Conference on Knowledge Discovery and Data Mining, page 70-87. (August 2004)
R. Dror, G. Baumer, S. Shlomov, and R. Reichart. Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), page 1383--1392. Association for Computational Linguistics, (2018)