4Robertson S E,Rijsbergen C J V,Porter M F.Probabilistic mod-els of indexing and searching[].SIGIR’:Proceedings ofthe rd annual ACM conference on Research and development ininformation retrieval.1980
5Lafferty J,Zhai Chengxiang.Document language models,querymodels,and risk minimization for information retrieval[].SI-GIR’:Proceedings of the th annual international ACM SI-GIR conference on research and development in information re-trieval.2001
6Metzler D,Croft W B.A markov random field model for termdependencies[].SIGIR’:Proceedings of the th annual inter-national ACM SIGIR conference on research and development ininformation retrieval.2005
7Rasolofo Y,Savoy J.Term proximity scoring for keyword-basedretrieval systems[].ECIR’:Proceedings th EuropeanConference on IR Research.2003
8Qiao Ya-nan,Qi Yong,He Hui.The Research on Term FieldBased Term Co-occurrence Model[].SKG’:Proceedingsof the Third International Conference on SemanticsKnowledgeand Grid.2001