@article{ioauto,
	author = "N. A. Lynch and E. W. Stark",
	title = "A Proof of the Kahn Principle for Input/Output Automata",
	journal = "Information and Computation",
	volume = 82,
	number = "1",
	month = JUL,
	pages = "81--92",
	year = 1989
}