204
WHITNEY, V.K.M., 'Minimal spanning tree, Algorithm 422', Communications of the ACM, 15, 273-274 (1972).

WILLIAMS, J.H., 'Results of classifying documents with multiple discriminant functions', In : Statistical Association Methods for Mechanized Documentation (Edited by Stevens et al.) National Bureau of Standards, Washington, 217-224 (1965).

WINDLEY, P.F., 'Trees, forests and rearranging', Computer Journal, 3, 84-88 (1960)

WINOGRAD, T., Understanding Natural Language, Edinburgh University Press, Edinburgh (1972).

WISHART, D., FORTRAN II Program for 8 Methods of Cluster Analysis (CLUSTAN I) Computer Contribution 38 State Geological Survey. The University of Kansas, Lawrence, Kansas, U.S.A. (1969).

YU, C.T., and LUK, W.S., 'Analysis of effectiveness of retrieval in clustered files', Journal of the ACM, 24, 607-622 (1977).

YU, C.T., LUK, W.S. and CHEUNG, T.Y., 'A statistical model for relevance feedback in information retrieval', Journal of the ACM, 23, 273-286 (1976).

YU, C.T., LUK, W.C. and SIU, M.K., 'On the estimation of the number of desired records with respect to a given party' (in preparation).

YU, C.T. and SALTON, G., "Precision Weighting - An effective automatic indexing method', Journal of the ACM, 23, 76-85 (1976).

YU, C.T. and SALTON, G., 'Effective information retrieval using term accuracy', Communications of the ACM, 20, 135-142 (1977).

ZADEH, L.A., 'Fuzzy sets', Information and Control, 8, 338-353 (1965).

ZADEH, L.A., 'Similarity relations and fuzzy orderings', Information Sciences, 3, 177-200 (1973).

ZIPF, H.P., Human Behaviour and the Principle of Least Effort,Addison-Wesley, Cambridge, Massachusetts (1949).


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