@InProceedings{GildeaHofmann99, author = {Daniel Gildea and Thomas Hofmann}, title = {Topic-Based Language Models Using {EM}}, booktitle = {Proceedings of the 6th European Conference on Speech Communication and Technology (EUROSPEECH-99)}, year = {1999}, pages = {2167--2170}, address = {Budapest}, URL = {http://www.cs.rochester.edu/~gildea/gildea_hofmann_99.ps} }