Eugene Agichtein Carlos Castillo Debora Donato Aristides Gionis Gilad Mishne Finding high-quality content in social media. 183-194 2008 conf/wsdm/2008 WSDM http://doi.acm.org/10.1145/1341531.1341557 db/conf/wsdm/wsdm2008.html#AgichteinCDGM08