@inproceedings{DBLP:conf/pricai/DelgrandeS98, author = {Delgrande, James P. and Schaub, Torsten}, title = {Reasoning with Sets of Preferences in Default Logic}, booktitle = {{PRICAI}}, series = {Lecture Notes in Computer Science}, volume = {1531}, pages = {134--145}, publisher = {Springer}, year = {1998} }