Gabi Koifman Onn Shehory Avigdor Gal Multi-agent negotiation and price discrimination for information goods. 1964-1971 2004 conf/smc/2004 SMC (2) http://dx.doi.org/10.1109/ICSMC.2004.1399980 db/conf/smc/smc2004-2.html#KoifmanSG04