5Palmer D, Day D S. A statistical Profile of the Named Entity Task [C];Proceedings of the 5th Confference on Applied Natural Language processing, Washington D. C., March 1997.
6Adam L Berger,B Pietra,V Pietra. A Maximum Entropy Approach to Natrual Language Processing [J] ; Computational Linguistics, 1996,22 ( 1 ): 39-71.
7Adwait Ratnaparkhi. Maximum Entropy Models For Natural Language Ambiguity Resolution [D] ;Ph.D Thesis,University Of Pennsylvania, 1998.