1. Accumo (2006). Accumo – enterprise text categorization – technology. Retrieved December 4, 2006, from .
2. Maximization technique occurring in statistical analysis of probabilistic functions in Markov chains;Baum;The Annals of Mathematical Statistics,1970
3. Conroy, J. M., & O’Leary, D. P. (2001). Text summarization via hidden Markov models and pivoted QR matrix decomposition. Tech. Rep., University of Maryland, College Park.
4. Conroy, J. M., Schlesinger, J. D., Goldstein, J., & O’Leary, D. P. (2004). Left-brain/right-brain multi-document summarization. In Proc. document understanding conference.
5. CyberTavern, LLC, (2006). iboogie – metasearch document clustering engine and personalized search engines directory. Retrieved December 4, 2006, from .