@inproceedings{STOC-2008-BartoKN,
	author        = "Libor Barto and Marcin Kozik and Todd Niven",
	booktitle     = "{Proceedings of the 40th Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/1374376.1374488",
	isbn          = "978-1-60558-047-0",
	pages         = "789--796",
	publisher     = "{ACM}",
	title         = "{Graphs, polymorphisms and the complexity of homomorphism problems}",
	year          = 2008,
}