@inproceedings{PODS-1996-Egenhofer,
	author        = "Max J. Egenhofer",
	booktitle     = "{Proceedings of the 15th Symposium on Principles of Database Systems}",
	doi           = "10.1145/237661.242785",
	isbn          = "0-89791-781-2",
	pages         = "80",
	publisher     = "{ACM Press}",
	title         = "{Geographic Database Systems: Issues and Research Needs}",
	year          = 1996,
}