D. Ramage, D. Hall, R. Nallapati, and C. Manning. Proceedings of the 2009 Conference on Empirical Methods in Natural Language Processing: Volume 1 - Volume 1, page 248--256. Stroudsburg, PA, USA, Association for Computational Linguistics, (2009)
M. Rosen-Zvi, T. Griffiths, M. Steyvers, and P. Smyth. Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI), San Francisco, CA, Morgan Kaufmann, (2004)