@inproceedings{STOC-1981-Simon,
	author        = "Janos Simon",
	booktitle     = "{Proceedings of the 13th Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/800076.802469",
	pages         = "158--167",
	publisher     = "{ACM}",
	title         = "{Space-Bounded Probabilistic Turing Machine Complexity Classes Are Closed under Complement}",
	year          = 1981,
}