@inproceedings{STOC-1987-MaassSS,
	author        = "Wolfgang Maass and Georg Schnitger and Endre Szemerédi",
	booktitle     = "{Proceedings of the 19th Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/28395.28406",
	isbn          = "0-89791-221-7",
	pages         = "94--100",
	publisher     = "{ACM}",
	title         = "{Two Tapes Are Better than One for Off-Line Turing Machines}",
	year          = 1987,
}