Eugene Agichtein Evgeniy Gabrilovich Hongyuan Zha The Social Future of Web Search: Modeling, Exploiting, and Searching Collaboratively Generated Content. 52-61 2009 32 IEEE Data Eng. Bull. 2 http://sites.computer.org/debull/A09June/agichtein_ssm1.pdf db/journals/debu/debu32.html#AgichteinGZ09