T. Wong, W. Lam, и T. Wong. SIGIR '08: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval, стр. 35--42. New York, NY, USA, ACM, (2008)
A. Arasu, и H. Garcia-Molina. Proceedings of the 2003 ACM SIGMOD International Conference on Management of Data, San Diego, California, USA, June 9-12, 2003, стр. 337-348. ACM, (2003)