1. Bird, S., & Loper, E. (2004). NLTK: The natural language toolkit, In Proceedings of the ACL demonstration session, Barcelona, Association for Computational Linguistics, July. (pp. 214–217).
2. Blitzer, J., Dredze, M., & Pereira, F. (2007). Biographies, bollywood, boom-boxes and blenders: Domain adaptation for sentiment classification. In Proceedings of annual meetings of association of computational linguistics (ACL).
3. Chang, C.-C., & Lin, C.-J. (2001). LIBSVM: a library for support vector machines. .
4. The effect of word of mouth on sales: Online book reviews;Chevalier;Journal of Marketing Research,2006
5. Dave, K., Lawrence, S., & Pennock, D.M. (2003). Mining the peanut gallery: Opinion extraction and semantic classification of product reviews, In Proceedings of WWW03, (pp. 519–528), May 20–24, Budapest, Hungary, ACM.