T. Joachims. Proceedings of ECML-98, 10th European Conference on Machine Learning, 1398, page 137--142. Chemnitz, DE, Springer Verlag, Heidelberg, DE, (1998)
B. Lauser, and A. Hotho. Proc. of the 7th European Conference in Research and Advanced Technology for Digital Libraries, ECDL 2003, volume 2769 of LNCS, page 140-151. Springer, (2003)
X. Li, B. Liu, and S. Ng. Proceedings of the 2010 Conference on Empirical Methods in Natural Language Processing, page 218--228. Stroudsburg, PA, USA, Association for Computational Linguistics, (2010)