@inproceedings{STOC-1974-EhrenfeuchtZ,
	author        = "Andrzej Ehrenfeucht and H. Paul Zeiger",
	booktitle     = "{Proceedings of the Sixth Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/800119.803886",
	pages         = "75--79",
	publisher     = "{ACM}",
	title         = "{Complexity Measures for Regular Expressions}",
	year          = 1974,
}