id: 70495319 dt: a an: 70495319 au: Ashkan, Azin; Clarke, Charles L. A.; Agichtein, Eugene; Guo, Qi ti: Estimating ad clickthrough rate through query intent analysis so: Web Intelligence, 222-229 (2009). py: 2009 pu: la: EN cc: ut: ci: li: doi:10.1109/WI-IAT.2009.39