S. Wu, J. Hofman, W. Mason, и D. Watts. Proceedings of the 20th International Conference on World Wide Web, стр. 705--714. New York, NY, USA, ACM, (2011)
A. Popescul, L. Ungar, D. Pennock, и S. Lawrence. Proceedings of the 17th Conference on Uncertainty in Artificial Intelligence, стр. 437--444. San Francisco, CA, USA, Morgan Kaufmann Publishers Inc., (августа 2001)