@inproceedings{SIGMOD-1987-AbiteboulKG,
	author        = "Serge Abiteboul and Paris C. Kanellakis and Gösta Grahne",
	booktitle     = "{Proceedings of the 17th ACM SIGMOD International Conference on Management of Data}",
	cdrom         = "SIGMOD87/P034.PDF",
	doi           = "10.1145/38713.38724",
	pages         = "34--48",
	title         = "{On the Representation and Querying of Sets of Possible Worlds}",
	year          = 1987,
}