Craig Boutilier Ronen I. Brafman Holger H. Hoos David Poole Reasoning With Conditional Ceteris Paribus Preference Statements. 71-80 1999 conf/uai/1999 UAI http://rome.exp.sis.pitt.edu/UAI/Abstract.asp?articleID=155&proceedingID=15 db/conf/uai/uai1999.html#BoutilierBHP99