@article{Minsky&Papert:1966,
	key = "Minsky and Papert 1966",
        author = "M. Minsky and S. Papert",
        title = "Unrecognizable sets of numbers",
        journal = JACM,
        volume = 13,
        year = 1966,
        pages = "281-286",
	comment = "checked"}

@article{Hartmanis&Shank:1968,
	key = "Hartmanis and Shank 1968",
	author = "J. Hartmanis and H. Shank",
	title = "On the recognition of primes by automata",
	journal = JACM,
	volume = 15,
	year = 1968,
	pages = "382-389"}

@article{Allen:1968,
	key = "Allen 1968",
	author = "Allen, Jr., D.",
	title = "On a characterization of the nonregular set of primes",
	journal = JCSS,
	volume = 2,
	year = 1968,
	pages = "464-467"}

@article{Hartmanis&Shank:1969,
	key = "Hartmanis and Shank 1969",
	author = "J. Hartmanis and H. Shank",
	title = "Two memory bounds for the recognition of primes by
automata",
	journal = MST,
	volume = 3,
	year = 1969,
	pages = "125-129"}

@article{Schutzenberger:1968,
	key = "{Sch\"utzenberger} 1968",
	author = "M. P. {Sch\"utzenberger}",
	title = "A remark on acceptable sets of numbers",
	journal = JACM,
	volume = 15,
	year = 1968,
	pages = "300-303"}