@inproceedings{ICALP-1977-Engelfriet,
	author        = "Joost Engelfriet",
	booktitle     = "{Proceedings of the Fourth Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/3-540-08342-1_17",
	isbn          = "3-540-08342-1",
	pages         = "221--229",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Macro Grammars, Lindenmayer Systems and Other Copying Devices}",
	volume        = 52,
	year          = 1977,
}