@Article{         Minsky:1961,
  Author        = "Minsky, Marvin L.",
  date-added    = "2019-03-05 19:57:07 +0100",
  date-modified = "2019-03-05 20:09:48 +0100",
  ISSN          = "0003486X",
  Journal       = "Annals of Mathematics",
  Number        = "3",
  Pages         = "437--455",
  Publisher     = "Annals of Mathematics",
  Title         = {Recursive Unsolvability of Post's Problem of "Tag" and other Topics in Theory of Turing Machines},
  URL           = "http://www.jstor.org/stable/1970290",
  Volume        = "74",
  Year          = "1961",
  bdsk-url-1    = "http://www.jstor.org/stable/1970290",
  File          = "1970290 (0) (0) - a - a - q.pdf"
}

@Article{ Minsky:1961, Author = "Minsky, Marvin L.", date-added = "2019-03-05 19:57:07 +0100", date-modified = "2019-03-05 20:09:48 +0100", ISSN = "0003486X", Journal = "Annals of Mathematics", Number = "3", Pages = "437--455", Publisher = "Annals of Mathematics", Title = {Recursive Unsolvability of Post's Problem of "Tag" and other Topics in Theory of Turing Machines}, URL = "http://www.jstor.org/stable/1970290", Volume = "74", Year = "1961", bdsk-url-1 = "http://www.jstor.org/stable/1970290", File = "1970290 (0) (0) - a - a - q.pdf" }