@inproceedings{ICALP-1995-EhrenfeuchtHR,
	author        = "Andrzej Ehrenfeucht and Tero Harju and Grzegorz Rozenberg",
	booktitle     = "{Proceedings of the 22nd International Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/3-540-60084-1_58",
	isbn          = "3-540-60084-1",
	pages         = "1--14",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Theory of 2-Structures}",
	volume        = 944,
	year          = 1995,
}