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@Book{            book:112833,
  Author        = "Smullyan, Raymond M.",
  date-added    = "2020-04-10 11:07:26 +0200",
  date-modified = "2020-04-10 11:07:26 +0200",
  ISBN          = "9780486683706,0486683702",
  Publisher     = "Dover Publications",
  Title         = "First-order logic",
  URL           = "http://gen.lib.rus.ec/book/index.php?md5=9970865F6E96121394A95E7FF50D3928",
  Year          = "1995",
  bdsk-url-1    = "http://gen.lib.rus.ec/book/index.php?md5=9970865F6E96121394A95E7FF50D3928",
  File          = "[Raymond\_M.\_Smullyan]\_First-Order\_Logic(z-lib.org) (0) - a - a.pdf",
  file-2        = "[Raymond\_M.\_Smullyan]\_First-Order\_Logic(z-lib.org) (0) - a - a.djvu"
}

@Book{ book:112833, Author = "Smullyan, Raymond M.", date-added = "2020-04-10 11:07:26 +0200", date-modified = "2020-04-10 11:07:26 +0200", ISBN = "9780486683706,0486683702", Publisher = "Dover Publications", Title = "First-order logic", URL = "http://gen.lib.rus.ec/book/index.php?md5=9970865F6E96121394A95E7FF50D3928", Year = "1995", bdsk-url-1 = "http://gen.lib.rus.ec/book/index.php?md5=9970865F6E96121394A95E7FF50D3928", File = "[Raymond_M._Smullyan]_First-Order_Logic(z-lib.org) (0) - a - a.pdf", file-2 = "[Raymond_M._Smullyan]_First-Order_Logic(z-lib.org) (0) - a - a.djvu" }