Adam Marcus 0002 Eugene Wu 0002 Samuel Madden Robert C. Miller Crowdsourced Databases: Query Processing with People. 211-214 2011 CIDR http://www.cidrdb.org/cidr2011/Papers/CIDR11_Paper29.pdf conf/cidr/2011 db/conf/cidr/cidr2011.html#MarcusWMM11