S. Doerfel, R. Jäschke, A. Hotho, und G. Stumme. Proceedings of the 4th ACM RecSys workshop on Recommender systems and the social web, Seite 9--16. New York, NY, USA, ACM, (2012)
F. Benevenuto, T. Rodrigues, M. Cha, und V. Almeida. Proceedings of the 9th ACM SIGCOMM Conference on Internet Measurement Conference, Seite 49--62. New York, NY, USA, ACM, (2009)