1. Grouplens: An open architecture for collaborative filtering of netnews;Resnick,1994
2. Social information filtering: Algorithms for automating “word of mouth”;Shardanand,1995
3. Recommending and evaluating choices in a virtual community of use;Hill,1995
4. Collective dynamics of ‘small-world’ networks;Watts;Nature,1998
5. Emergence of scaling in random networks;Barabási;Science,1999