@inproceedings{STOC-1977-Paul,
	author        = "Wolfgang J. Paul",
	booktitle     = "{Proceedings of the Ninth Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/800105.803411",
	pages         = "218--222",
	publisher     = "{ACM}",
	title         = "{On Time Hierarchies}",
	year          = 1977,
}