@inproceedings{ICLP-1999-Zhang,
	author        = "Yan Zhang",
	booktitle     = "{Proceedings of the 15th International Conference on Logic Programming}",
	isbn          = "0-262-54104-1",
	pages         = "471--485",
	publisher     = "{MIT Press}",
	title         = "{Monotonicity in Rule Based Update}",
	year          = 1999,
}