@inproceedings{ICALP-1984-RestivoR,
	author        = "Antonio Restivo and Christophe Reutenauer",
	booktitle     = "{Proceedings of the 11th Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/3-540-13345-3_38",
	isbn          = "3-540-13345-3",
	pages         = "414--422",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Cancellation, Pumping and Permutation in Formal Languages}",
	volume        = 172,
	year          = 1984,
}