@inproceedings{LICS-2003-FederV,
	author        = "Tomás Feder and Moshe Y. Vardi",
	booktitle     = "{Proceedings of the 18th IEEE Symposium on Logic in Computer Science}",
	doi           = "10.1109/LICS.2003.1210071",
	isbn          = "0-7695-1884-2",
	pages         = "311--320",
	publisher     = "{IEEE Computer Society}",
	title         = "{Homomorphism Closed vs. Existential Positive}",
	year          = 2003,
}