Craig Boutilier Moisés Goldszmidt Bikash Sabata Continuous Value Function Approximation for Sequential Bidding Policies. 81-90 1999 conf/uai/1999 UAI http://rome.exp.sis.pitt.edu/UAI/Abstract.asp?articleID=156&proceedingID=15 db/conf/uai/uai1999.html#BoutilierGS99