D. Gruhl, R. Guha, D. Liben-Nowell, and A. Tomkins. WWW '04: Proceedings of the 13th international conference on World Wide Web, page 491--501. New York, NY, USA, ACM, (2004)Very good paper on information diffusion..
R. Kumar, J. Novak, and A. Tomkins. KDD '06: Proceedings of the 12th ACM SIGKDD international conference on Knowledge discovery and data mining, page 611--617. New York, NY, USA, ACM, (2006)