1. Dorsey, J. (2006). Just setting up my twttr. Twitter. Oldest Tweet ever from Twitter founder.
2. Dave, K., Lawrence, S., & Pennock, D. (2003). Mining the peanut gallery: Opinion extraction and semantic classification of product reviews. In Proceedings of the 12th international conference on World Wide Web (pp. 519–528).
3. Nasukawa, T., & Yi, J. (2003). Sentiment analysis: Capturing favorability using natural language processing. In Proceedings of the 2nd international conference on Knowledge capture (pp. 70–77).
4. Kim, S. M., & Hovy, E. (2005). Automatic detection of opinion bearing words and sentences. In Companion Volume to the Proceedings of the International Joint Conference on Natural Language Processing (IJCNLP), Vol. 8.
5. Pang, B., Lee, L., & Vaithyanathan, S. (2002). Thumbs up?: Sentiment classification using machine learning techniques. In Proceedings of the ACL-02 conference on empirical methods in natural language Processing-Volume, Association for Computational Linguistics, Vol. 10 (pp. 79–86).