Animesh Animesh Vandana Ramachandran Siva Viswanathan An empirical investigation of the performance of online sponsored search markets. 153-160 2007 conf/ACMicec/2007 ICEC http://doi.acm.org/10.1145/1282100.1282132 db/conf/ACMicec/icec2007.html#AnimeshRV07