1. M. Diligenti, F. Coetzee, S. Lawrence, C.L. Giles, M. Gori, Focused crawling using context graphs, in: Proceedings of the 26th International Conference on Very Large Databases, VLDB 2000, Cairo, Egypt, http://www.neci.nec.com/lawrence/papers/focus-vldb00/focus-vldb00.ps.gz.
2. J. Cho, H. Garcı́a-Molina, L. Page, Efficient crawling through URL ordering, Computer Networks and ISDN Systems 30 (1–7) (1998) 161–172, http://www-db.stanford.edu/pub/papers/efficient-crawling.ps.
3. J. Dean, M. Henzinger, Finding related pages in the world wide web, WWW8/Computer Networks 31 (11–16) (1999) 1467–1479, http://www.research.compaq.com/SRC/personal/monika/papers/monika-www8-1.ps.gz.
4. S. Chakrabarti, D. Gibson, K. McCurley, Surfing the Web backwards, in: Proceedings of the 8th World Wide Web Conference, Toronto, Canada, 1999, http://www8.org/w8-papers/5b-hypertext-media/surfing/.
5. A. McCallum, K. Nigam, J. Rennie, K. Seymore, Building domain-specific search engines with machine learning techniques, AAAI-99 Spring Symposium on Intelligent Agents in Cyberspace, 1999, http://www.cs.cmu.edu/mccallum/papers/cora-aaaiss98.ps.