Z. Bar-Yossef, T. Jayram, R. Kumar, D. Sivakumar, and L. Trevisan. Proceedings of the 6th International Workshop on Randomization and Approximation Techniques (RANDOM), page 1--10. Cambridge, Ma, USA, Springer-Verlag, (September 2002)
D. Gruhl, R. Guha, R. Kumar, J. Novak, and A. Tomkins. KDD '05: Proceeding of the eleventh ACM SIGKDD international conference on Knowledge discovery in data mining, page 78--87. New York, NY, USA, ACM Press, (2005)