@inproceedings{ICALP-1985-Chrobak,
	author        = "Marek Chrobak",
	booktitle     = "{Proceedings of the 12th Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/BFb0015735",
	isbn          = "3-540-15650-X",
	pages         = "101--110",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Hierarchies of One-Way Multihead Automata Languages}",
	volume        = 194,
	year          = 1985,
}