@inproceedings{ILPS-1997-VerbaetenDS,
	author        = "Sofie Verbaeten and Marc Denecker and Danny De Schreye",
	booktitle     = "{Proceedings of the International Symposium on Logic Programming}",
	isbn          = "0-262-63180-6",
	pages         = "371--385",
	publisher     = "{MIT Press}",
	title         = "{Compositionality of Normal Open Logic Programs}",
	year          = 1997,
}