Milan Bradonjic Gunes Ercal-Ozkaya Adam Meyerson Alan Roytman On the price of mediation. 315-324 2009 ACM Conference on Electronic Commerce http://doi.acm.org/10.1145/1566374.1566419 conf/sigecom/2009 db/conf/sigecom/sigecom2009.html#BradonjicEMR09