[1]LIEBERMAN H.Letizia: an Agent that assists Web browsing[A].Proceedings of the 14th International Joint Conference on Artificial Intelligence(IJCAI-95)[C].Montreal,Canada: Morgan Kanfmann,1995.924-929.
[2]BALABANOVIC M,SHOHAM Y.Fab:content-based,collaborative recommendation[J].Communication of the ACM,1997,40(3): 66-72.