✓

@Book{            KuichSalomaa:1986,
  Author        = "Kuich, Werner and Salomaa, Arto",
  date-added    = "2020-04-10 11:07:26 +0200",
  date-modified = "2020-06-11 09:00:35 +0200",
  DOI           = "10.1007/978-3-642-69959-7",
  ISBN          = "978-3-642-69961-0,978-3-642-69959-7",
  Publisher     = "Springer",
  Series        = "EATCS Monographs on Theoretical Computer Science 5",
  Title         = "Semirings, Automata, Languages",
  URL           = "http://gen.lib.rus.ec/book/index.php?md5=c22e327ec8a3a010137c7809f7a5abe1",
  Year          = "1986",
  File          = "Semirings, Automata, Languages.pdf"
}

@Book{ KuichSalomaa:1986, Author = "Kuich, Werner and Salomaa, Arto", date-added = "2020-04-10 11:07:26 +0200", date-modified = "2020-06-11 09:00:35 +0200", DOI = "10.1007/978-3-642-69959-7", ISBN = "978-3-642-69961-0,978-3-642-69959-7", Publisher = "Springer", Series = "EATCS Monographs on Theoretical Computer Science 5", Title = "Semirings, Automata, Languages", URL = "http://gen.lib.rus.ec/book/index.php?md5=c22e327ec8a3a010137c7809f7a5abe1", Year = "1986", File = "Semirings, Automata, Languages.pdf" }