Yu Zhang Huajun Chen Hao Sheng Zhaohui Wu Applying Hypothetical Queries to E-Commerce Systems to Support Reservation and Personal Preferences. 46-53 2007 conf/ideas/2007 IDEAS http://doi.ieeecomputersociety.org/10.1109/IDEAS.2007.15 db/conf/ideas/ideas2007.html#ZhangCSW07