9Cover T M, Hart P E. Nearest neighbor pattern classification[ J ]. IEEE Transactions on Information Theory, 1967,13 ( 1 ) : 21 - 27.
10Yang Yiming, Pedersen J O. A comparative study on feature selec- tion in text categorization [ C ]//Proceedings of the Fourteenth Inter- national Conference on Machine Learning (ICML' 97 ). San Fran-cisco: Morgan Kaufman Publishers, 1997:412 - 420.