Ioannis Antonellis Hector Garcia-Molina Jawed Karim Tagging with Queries: How and Why? 2009 WSDM (Late Breaking-Results) http://www.wsdm2009.org/wsdm2009_antonellis.pdf conf/wsdm/2009 db/conf/wsdm/wsdm2009.html#AntonellisGK09