T. Joachims. Proceedings of the eighth ACM SIGKDD international conference on Knowledge discovery and data mining, Seite 133--142. New York, NY, USA, ACM, (2002)
Y. Zhou, und W. Croft. Proceedings of the 14th ACM International Conference on Information and Knowledge Management, Seite 331--332. New York, NY, USA, ACM, (2005)