@inproceedings{STOC-1971-Robertson,
	author        = "Edward L. Robertson",
	booktitle     = "{Proceedings of the Third Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/800157.805055",
	pages         = "258--266",
	publisher     = "{ACM}",
	title         = "{Complexity Classes of Partial Recursive Functions}",
	year          = 1971,
}