@book{DeneckeTodorov1994,
  author    = {Denecke, Klaus-Dieter and Todorov, Kalco},
  title     = {Algebraische Grundlagen der Arithmetik},
  series = {Berliner Studienreihe zur Mathematik},
  volume    = {4},
  journal   = {Berliner Studienreihe zur Mathematik},
  publisher = {Heldermann},
  address   = {Berlin},
  pages     = {VIII, 200 S.},
  year      = {1994},
  language  = {de}
}
@book{DeneckeTodorov1996,
  author    = {Denecke, Klaus-Dieter and Todorov, Kalco},
  title     = {Allgemeine Algebra und Anwendungen},
  publisher = {Shaker},
  address   = {Aachen},
  pages     = {251 S.},
  year      = {1996},
  language  = {de}
}
@book{DeneckeTodorov1999,
  author    = {Denecke, Klaus-Dieter and Todorov, Kalco},
  title     = {Osnovi na Aritmetikata},
  publisher = {Univ. Press},
  address   = {Blagoevgrad [Bulgarian]},
  isbn      = {954-680-122-4},
  year      = {1999},
  language  = {de}
}