S. Xu, S. Bao, B. Fei, Z. Su, и Y. Yu. Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval, стр. 155--162. New York, NY, USA, ACM, (2008)
P. Heymann, G. Koutrika, и H. Garcia-Molina. Proceedings of the 2008 International Conference on Web Search and Data Mining, стр. 195--206. New York, NY, USA, ACM, (2008)