B. Pinkerton. Proceedings of the 2nd International World Wide Web, том 18(6) из Online & CDROM review: the international journal of, Medford, NJ, USA, Learned Information, (1994)
J. Ding, L. Gravano, и N. Shivakumar. Proceedings of the 26th Int. Conf. on Very Large Databases, VLDB 2000, стр. 545--556. Morgan Kaufmann Publishers Inc., (2000)