@inproceedings{PODS-1998-SegoufinV,
	author        = "Luc Segoufin and Victor Vianu",
	booktitle     = "{Proceedings of the 17th Symposium on Principles of Database Systems}",
	cdrom         = "['journals/anthology/cd1-3:PODS98/P089.PDF', 'journals/anthology/dvd1:text/1-3/PODS98/P089.PDF']",
	doi           = "10.1145/275487.275498",
	isbn          = "0-89791-996-3",
	pages         = "89--98",
	publisher     = "{ACM Press}",
	title         = "{Querying Spatial Databases via Topological Invariants}",
	year          = 1998,
}