5Luhn H P. A business intelligence system [J]. IBM Journal of Research and Development, 1958, 2(04):314 - 319.
6Edward M Housman. Survey of current systems for selective dissemination of information. Technical Report SIG P SDI [R]. American Society for Information Science Special Interest Group on SDI, 1969.
7Peter J. Denning. Electronic junk [J]. Communications of the ACM, 1982, 25 (03) :163-165.
8Thomas W Malone, Kenneth R Grant, Franklyn A Turbak, et al. Intelligent information sharing systems [J]. Communications Of the ACM, 1987, 28 (06):390-402.