@inproceedings{ICALP-1983-Perrin,
	author        = "Dominique Perrin",
	booktitle     = "{Proceedings of the 10th Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/BFb0036941",
	isbn          = "3-540-12317-2",
	pages         = "610--616",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Varietes de Semigroupes et Mots Infinis}",
	volume        = 154,
	year          = 1983,
}