Yuko Sakurai Atsushi Iwasaki Makoto Yokoo Keyword Auction Protocol for Dynamically Adjusting the Number of Advertisements. 410-416 2008 IAT http://dx.doi.org/10.1109/WIIAT.2008.218 conf/iat/2008 db/conf/iat/iat2008.html#SakuraiIY08