@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}
}
@article{Denecke1999,
  author    = {Denecke, Klaus-Dieter},
  title     = {Clones closed with respect to closed operators},
  year      = {1999},
  language  = {en}
}
@article{DeneckeFreiberg1998,
  author    = {Denecke, Klaus-Dieter and Freiberg, L.},
  title     = {The word problem for M-solid varieties of semigroups},
  isbn      = {981-3083-86-7},
  year      = {1998},
  language  = {en}
}
@article{DeneckePlonka1995,
  author    = {Denecke, Klaus-Dieter and Plonka, J.},
  title     = {Regularization and normalization of solid varieties},
  year      = {1995},
  language  = {en}
}
@article{DeneckeReichel1995,
  author    = {Denecke, Klaus-Dieter and Reichel, Mario},
  title     = {Monoids of hypersubstitutions and m-solid varieties},
  year      = {1995},
  language  = {en}
}
@article{DeneckePlonka1995,
  author    = {Denecke, Klaus-Dieter and Plonka, J.},
  title     = {Edge-solid varieties},
  year      = {1995},
  language  = {en}
}
@article{DeneckeMalcevReschke1995,
  author    = {Denecke, Klaus-Dieter and Malcev, I. A. and Reschke, M.},
  title     = {On separation of Boolean clones by means of hyperidentities},
  year      = {1995},
  language  = {en}
}
@article{DeneckeKoppitz1995,
  author    = {Denecke, Klaus-Dieter and Koppitz, J{\"o}rg},
  title     = {Pre-solid varieties of commutative semigroups},
  year      = {1995},
  language  = {en}
}
@article{DeneckeKoppitz1995,
  author    = {Denecke, Klaus-Dieter and Koppitz, J{\"o}rg},
  title     = {M-solid varieties of semigroups},
  year      = {1995},
  language  = {en}
}
@article{DeneckeKoppitz1995,
  author    = {Denecke, Klaus-Dieter and Koppitz, J{\"o}rg},
  title     = {Pre-solid varieties of semigroups},
  year      = {1995},
  language  = {en}
}