@inproceedings{PODS-2002-ArenasL,
	author        = "Marcelo Arenas and Leonid Libkin",
	booktitle     = "{Proceedings of the 21st Symposium on Principles of Database Systems}",
	doi           = "10.1145/543613.543625",
	ee            = "http://www.acm.org/sigs/sigmod/pods/proc02/papers/085-ArenasL.pdf",
	isbn          = "1-58113-507-6",
	pages         = "85--96",
	publisher     = "{ACM}",
	title         = "{A Normal Form for XML Documents}",
	year          = 2002,
}