1. Schreiner T. New compete study: primary mobile users on twitter. 2011. https://www.blog.twitter.com/2013/new-compete-study-primary-mobile-users-on-twitter .
2. Heggestuen J. One in every 5 people in the world own a smartphone, one in every 17 own a tablet. 2013.
3. Tsukayama H. Twitter turns 7: Users send over 400 million tweets per day. 2013.
4. Sriram B, Fuhry D, Demir E, Ferhatosmanoglu H, Demirbas M. Short text classification in twitter to improve information filtering. In SIGIR’10. New York: ACM. 2010.
5. Garcia Esparza S, O’Mahony MP, Smyth B. Towards tagging and categorization for micro-blogs. 2010.