IR-199: (2000) Powell, A.,  French, J.,  Callan, J.,  Connell, M. and Viles, C., "The Impact of Database Selection on Distributed Searching," SIGIR 2000, pp. 232-239. [View bibtex]
IR-181: (1999) Callan, J.,  Powell, A.,  French, J. and Connell, M., "The Effects of Query-Based Sampling on Automatic Database Selection Algorithms," CIIR Technical Report. No electronic copy available. [View bibtex]
IR-167: (1999) French, J.,  Powell, A. and Callan, J., "Effective and efficient automatic database selection," CIIR Technical Report. [View bibtex]
IR-161: (1999) French, J.,  Powell, A.,  Callan, J.,  Viles, C.,  Emmitt, T.,  Prey, K. and Mou, Y., "Comparing the Performance of Database Selection Algorithms," Proceedings of the 22nd International ACM SIGIR Conference on Research and Development Information Retrieval (SIGIR 99), pp. 238-245. [View bibtex]