@inproceedings{STOC-1972-WalkerS,
	author        = "S. A. Walker and H. Raymond Strong",
	booktitle     = "{Proceedings of the Fourth Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/800152.804893",
	pages         = "18--34",
	publisher     = "{ACM}",
	title         = "{Characterization of Flowchartable Recursions}",
	year          = 1972,
}