@inproceedings{ICALP-1974-Book,
	author        = "Ronald V. Book",
	booktitle     = "{Proceedings of the Second Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/3-540-06841-4_80",
	isbn          = "3-540-06841-4",
	pages         = "437--445",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{On the Structure of Complexity Classes}",
	volume        = 14,
	year          = 1974,
}