6Davenport, T H , Information Ecology: Mastering Information & Knowledge Environment,Oxford Univ. Press, 1997.
7Hsinchun Chen, Bruce Schatz, Tobun Ng. A Parallel Computing Approach to Creating Engineering Concept Spaces for Semantic Retrieval:The Illinois Digital Library Initiative Project. http://ai.bpa. arizona.edu/papers/pami96/pami96.html (Accessed Jan. 12,2003).
8C. Y. Ng,Joseph Lee,Felix Cheung. Algorithms for Concept Space Construction. http://citeseer. nj. nec. com/583849.html (Accessed Jan. 12,2003).
9Andrea L. Houston, Hsinchun Chen, Bruce R. Schatz. Exploring the use of concept spaces to improve medical information retrieval.http://ai.bpa. arizona. edu/go/intranet/papers/Exploring - 00.Pdf (Accessed Jan. 15,2003).
10Hsin chun Chen, Joanne Martinez, Amy Kirchhoff. Alleviating Search Uncertainty through Concept Associations: Automatic Indexing, Co -- Occurrence Analysis, and Parallel Computing.http://ai. bpa. arizona. edu/go/intranet/papers/Alleviating- 98.odf(Accessed Jan. 3,2003).