@Article{         Mckinsey:JSL:1939,
  Author        = "McKinsey, J. C. C.",
  date-added    = "2020-03-15 08:31:23 +0100",
  date-modified = "2020-03-15 08:31:43 +0100",
  fjournal      = "Journal of Symbolic Logic",
  Journal       = "J. Symbolic Logic",
  Month         = "12",
  Number        = "4",
  Pages         = "155--158",
  Publisher     = "Association for Symbolic Logic",
  Title         = "Proof of the Independence of the Primitive Symbols of Heyting's Calculus of Propositions",
  URL           = "https://projecteuclid.org:443/euclid.jsl/1183386722",
  Volume        = "4",
  Year          = "1939",
  bdsk-url-1    = "https://projecteuclid.org:443/euclid.jsl/1183386722",
  File          = "Proof of the Independence of the Primitive Symbols of Heyting's Calculus of Propositions - mckinsey1939 - a - a - a - r.pdf"
}

@Article{ Mckinsey:JSL:1939, Author = "McKinsey, J. C. C.", date-added = "2020-03-15 08:31:23 +0100", date-modified = "2020-03-15 08:31:43 +0100", fjournal = "Journal of Symbolic Logic", Journal = "J. Symbolic Logic", Month = "12", Number = "4", Pages = "155--158", Publisher = "Association for Symbolic Logic", Title = "Proof of the Independence of the Primitive Symbols of Heyting's Calculus of Propositions", URL = "https://projecteuclid.org:443/euclid.jsl/1183386722", Volume = "4", Year = "1939", bdsk-url-1 = "https://projecteuclid.org:443/euclid.jsl/1183386722", File = "Proof of the Independence of the Primitive Symbols of Heyting's Calculus of Propositions - mckinsey1939 - a - a - a - r.pdf" }