1. Twitter. http://www.twitter.com
2. Techcrunch. http://techcrunch.com/2012/07/30/analyst-twitter-passed-500m-users-in-june-2012-140m-of-them-in-us-jakarta-biggest-tweeting-city/
3. Twitter blog. http://blog.twitter.com/2012/03/twitter-turns-six.html
4. Cha M, Haddadi H, Gummadi PK (2010) Measuring user influence in Twitter: the million follower fallacy. In: Proceedings of AAAI ICWSM
5. Honeycutt C, Herring SC (2009) Beyond microblogging: conversation and collaboration via Twitter. In: Proceedings of Hawaii international conference on system sciences