@inproceedings{SIGMOD-1988-Borgida,
	author        = "Alexander Borgida",
	booktitle     = "{Proceedings of the 18th ACM SIGMOD International Conference on Management of Data}",
	cdrom         = "SIGMOD88/P434.PDF",
	doi           = "10.1145/50202.50254",
	pages         = "434--443",
	title         = "{Modeling Class Hierarchies with Contradictions}",
	year          = 1988,
}