@inproceedings{PPDP-2004-Lopez-FraguasRV,
	author        = "Francisco Javier López-Fraguas and Mario Rodríguez-Artalejo and Rafael del Vado Vírseda",
	booktitle     = "{Proceedings of the Sixth International Conference on Principles and Practice of Declarative Programming}",
	doi           = "10.1145/1013963.1013972",
	isbn          = "1-58113-819-9",
	pages         = "43--54",
	publisher     = "{ACM}",
	title         = "{A lazy narrowing calculus for declarative constraint programming}",
	year          = 2004,
}