@article{ChajadaDeneckeHalas1999,
  author    = {Chajada, I. and Denecke, Klaus-Dieter and Halas, R.},
  title     = {Algebras induced by hypersubstitutions},
  year      = {1999},
  language  = {en}
}
@phdthesis{ArwornDenecke1999,
  author    = {Arworn, Srichan and Denecke, Klaus-Dieter},
  title     = {Sets of hypersubstitutions and set-solid varieties},
  year      = {1999},
  language  = {en}
}
@article{DeneckeKoppitz1999,
  author    = {Denecke, Klaus-Dieter and Koppitz, J{\"o}rg},
  title     = {Normal forms of hypersubstitutions},
  year      = {1999},
  language  = {en}
}
@article{DeneckeLeeratanavalee1999,
  author    = {Denecke, Klaus-Dieter and Leeratanavalee, Sorasak},
  title     = {Weak hypersubstitutions and weakly derived algebras},
  year      = {1999},
  language  = {en}
}
@article{ArwornDenecke1999,
  author    = {Arworn, Srichan and Denecke, Klaus-Dieter},
  title     = {Left-edges solid varieties of differential groupoids},
  year      = {1999},
  language  = {en}
}
@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{DeneckeKoppitz1999,
  author    = {Denecke, Klaus-Dieter and Koppitz, J{\"o}rg},
  title     = {A characterization of M-solid varieties of semigroups},
  year      = {1999},
  language  = {en}
}
@article{DeneckeJampachon1999,
  author    = {Denecke, Klaus-Dieter and Jampachon, Prakit},
  title     = {Regular-solid varieties of commutative and idempotent groupoids},
  year      = {1999},
  language  = {en}
}
@article{DomschLueckEisenreich1999,
  author    = {Domsch, Horst and L{\"u}ck, Erika and Eisenreich, Manfred},
  title     = {Bestimmung der elektrischen Leitf{\"a}higkeit des Bodens mit dem Meßger{\"a}t EM 38 von Geonics zur Kennzeichnung der Verteilung sich unterscheidender Bodenprofile = Determination of the electrical soil bulk conductivity with the Geonics EM 38 for the identification of the soil types distribution},
  year      = {1999},
  language  = {de}
}