@inproceedings{STOC-1974-LadnerLS,
	author        = "Richard E. Ladner and Nancy A. Lynch and Alan L. Selman",
	booktitle     = "{Proceedings of the Sixth Annual ACM Symposium on Theory of Computing}",
	doi           = "10.1145/800119.803891",
	pages         = "110--121",
	publisher     = "{ACM}",
	title         = "{Comparisons of Polynomial-Time Reducibilities}",
	year          = 1974,
}