Charles L. A. Clarke, Egidio L. Terra. Passage retrieval vs. document retrieval for factoid question answering. In SIGIR 2003: Proceedings of the 26th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, July 28 - August 1, 2003, Toronto, Canada. pages 427-428, ACM, 2003. [doi]
Abstract is missing.