Retrieved June 12, 2000 from www.cis.upenn.edu/ϳungar/papers.htmlUngar, L.H.,and Foster, D.P., Clustering methods for collaborative filtering. In... LH Ungar,DP Foster 被引量: 980发表: 2000年 Fortnightly Review: How can impact factors be improved? Garfield, Eugene. How can impact ...