J. Leskovec, L. Backstrom, R. Kumar, and A. Tomkins. KDD '08: Proceeding of the 14th ACM SIGKDD international conference on Knowledge discovery and data mining, page 462--470. New York, NY, USA, ACM, (2008)
J. Kunegis, A. Lommatzsch, and C. Bauckhage. Proceedings of the 18th international conference on World wide web, page 741--750. New York, NY, USA, ACM, (2009)