@inproceedings{STOC-2004-AlurM,
	author        = "Rajeev Alur and P. Madhusudan",
	booktitle     = "{Proceedings of the 36th Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/1007352.1007390",
	isbn          = "1-58113-852-0",
	pages         = "202--211",
	publisher     = "{ACM}",
	title         = "{Visibly pushdown languages}",
	year          = 2004,
}