@inproceedings{STOC-1972-HechtU,
	author        = "Matthew S. Hecht and Jeffrey D. Ullman",
	booktitle     = "{Proceedings of the Fourth Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/800152.804919",
	pages         = "238--250",
	publisher     = "{ACM}",
	title         = "{Flow Graph Reducibility}",
	year          = 1972,
}