M. Hu, S. Liu, F. Wei, Y. Wu, J. Stasko, and K. Ma. Proceedings of the 2012 ACM annual conference on Human Factors in Computing Systems, page 2751--2754. ACM, (2012)
S. Petrović, M. Osborne, and V. Lavrenko. Human Language Technologies: The 2010 Annual Conference of the North American Chapter of the Association for Computational Linguistics, page 181--189. Association for Computational Linguistics, (2010)