Collaborative Value Filtering on the Web. - Gerard Rodríguez-Mulà; Hector Garcia-Molina; Andreas Paepcke (Comput. Networks, 1998)

Beyond Document Similarity: Understanding Value-Based Search and Browsing Technologies. - Andreas Paepcke; Hector Garcia-Molina; Gerard Rodríguez-Mulà; Junghoo Cho (SIGMOD Rec., 2000)