T. Joachims. Proceedings of the eighth ACM SIGKDD international conference on Knowledge discovery and data mining, page 133--142. New York, NY, USA, ACM, (2002)
G. Paltoglou, and M. Thelwall. Proceedings of the 48th Annual Meeting of the Association for Computational Linguistics, page 1386--1395. Association for Computational Linguistics, (2010)