7Katz, B. (1997). From sentence processing to information access on the World Wide Web. In Natural LanguageProcessing for the World Wide Web: Papers from the 1997 AAAI Spring Symposium [M]. California: AAAI, 1997.
8Kupiec, J. Murax: Arobust linguistic approach for question answering using an on-line encyclopedia[A]. In Proceedings of the 16th SIGIR Conference[C]. New York: ACM,2001:150-161.
9Abney, S., Collins, M. & Singhal, A. Answer extraction[R]. In The Proceedings of ANLP 2000. Morgan Kaufman,2000:296-301.
10Clarke, C.L.A., Cormaek, GV., Kisman, D.I.E. & Lynam, T.R. (2000). Question answering by passage selection (multitext experiments for TREC-9)[R]. In NIST Special Publication500-249: The Ninth Text REtrieval Conference (TREC 9). Maryland: NIST:673 - 683.
