1. G. Beverungen and J. Kalita. Evaluating methods for summarizing twitter posts. In Proceedings of International AAAI Conference on Web and Social Media (ICWSM), 11:9--12, 2011.
2. S. Bird, E. Klein, and E. Loper. Natural Language Processing with Python. O'Reilly Media Inc., 2009.
3. D. Chakrabarti and K. Punera. Event Summarization Using Tweets. In International Conference on Weblogs and Social Media (ICWSM), 2011.
4. M. Chaput. stemming 1.0: Python package index. https://pypi. python. org/pypi/stemming/1. 0, 2017.
5. eMarketer. Worldwide Social Network Users: 2013 Forecast and Comparative Estimates. Technical report, eMarketer, 2013.