1. J. A. Aslam and M. Montague. Models for metasearch. In Croft et~al. {7}, pages 276--284.
2. B. T. Bartell. Optimizing Ranking Functions: A Connectionist Approach to Adaptive Information Retrieval. PhD thesis, University of California, San Diego, 1994.
3. B. T. Bartell, G. W. Cottrell, and R. K. Belew. Automatic combination of multiple ranked retrieval systems. In W. B. Croft and C. van Rijsbergen, editors, SIGIR'94, Proceedings of the 17th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, pages 173--181, Dublin, Ireland, July 1994. Springer-Verlag, London.
4. N. Belkin, P. Kantor, C. Cool, and R. Quatrain. Combining evidence for information retrieval. In Harman {15}, pages 35--43.
5. N. Craswell, D. Hawking, and P. Thistlewaite. Merging results from isolated search engines. In Proceedings of the Tenth Australasian Database Conference, Aukland, New Zealand, Jan. 1999. Springer-Verlag.