3A. Java, X. Song, T. Finin, et al. Why we twitter: understanding microblogging usage and communities. [C]//Proceedings of the 9th WebKDD and 1st SNAKDD 2007 Workshop on Web Mining and Social Network Analysis, 2007: 56-65.
4H. Kwak, C. Lee, H. Park, et al. What is Twitter, a social network or a news media[C]//Proceedings of the International Conference on Word Wide Web (WWW), 2010: 591-600.
5S. Wu, J. M. Hofman, W. A. Mason, et al. Who says what to whom on Twitter[C]//Proceedings of the International Conference on World Wide Web (WWW), 2011: 705-714.
6M. Gupte, P. Shankar, J. Li, et al. Finding hierarchy in directed online social networks[C]//Proeeedings of the International Conference on World Wide Web (WWW) , 2011: 557-566.
7A. Arasu, J. Cho, H. Garcia-Molina, et al. Searching the web [J]. ACM Transactions on Internet Technology, 2001, 1(1): 2-43.
8J. Weng, E. Lim, J. Jiang, et al. TwitterRank: finding topic-sensitive influential twitterers[C]//Proceedings of the ACM Conference on Web Search and Data Mining (WSDM), 2010: 261-270.
9M. Cha, H. Haddadi, F. Benevenuto, K. P. Gummad. Measuring user influence on twitter., the million follower fallacy[C]//Proceedings of the 4th International AAAI Conference on Weblogs and Social Media, 2010.
10E. Bakshy, J. M. Hofman, W. A. Mason, et al. Everyone's an influencer: quantifying influence on Twitter[C]//Proceedings of the ACM Conference on Web Search and Data Mining (WSDM), 2011: 65-74.
