@incollection{SchulteLittkemann2006,
  author    = {Schulte, K. and Littkemann, J.},
  title     = {Investitionscontrolling},
  series = {Littkemann, J. (Hrsg.): Unternehmenscontrolling - Konzepte, Instrumente, praktische Anwendungen mit durchg{\"a}ngiger Fallstudie},
  booktitle = {Littkemann, J. (Hrsg.): Unternehmenscontrolling - Konzepte, Instrumente, praktische Anwendungen mit durchg{\"a}ngiger Fallstudie},
  publisher = {NWB},
  address   = {Herne/Berlin},
  isbn      = {3482569215},
  pages     = {555 -- 666},
  year      = {2006},
  language  = {mul}
}
@incollection{SchulteLittkemann2005,
  author    = {Schulte, K. and Littkemann, J.},
  title     = {Einbindung externer Berater in Innovationsprojekte},
  series = {Littkemann, J. (Hrsg.): Innovationscontrolling},
  booktitle = {Littkemann, J. (Hrsg.): Innovationscontrolling},
  publisher = {Vahlen},
  address   = {M{\"u}nchen},
  isbn      = {380063161X},
  pages     = {197 -- 219},
  year      = {2005},
  language  = {mul}
}
@book{LittkemannHoltupSchulte2009,
  author    = {Littkemann, J. and Holtup, M. and Schulte, K.},
  title     = {Buchf{\"u}hrung: Grundlagen - {\"U}bungen - Klausurvorbereitung},
  edition   = {4. Aufl.},
  publisher = {Gabler},
  address   = {Wiesbaden},
  isbn      = {3834919144},
  year      = {2009},
  language  = {mul}
}
@book{LittkemannHoltupSchulte2008,
  author    = {Littkemann, J. and Holtup, M. and Schulte, K.},
  title     = {Buchf{\"u}hrung: Grundlagen - {\"U}bungen - Klausurvorbereitung},
  edition   = {3. Aufl.},
  publisher = {Gabler},
  address   = {Wiesbaden},
  isbn      = {3834908576},
  year      = {2008},
  language  = {mul}
}
@book{LittkemannHoltupSchulte2007,
  author    = {Littkemann, J. and Holtup, M. and Schulte, K.},
  title     = {Buchf{\"u}hrung: Grundlagen - {\"U}bungen - Klausurvorbereitung},
  edition   = {2. Aufl.},
  publisher = {Gabler},
  address   = {Wiesbaden},
  isbn      = {3834905585},
  year      = {2007},
  language  = {mul}
}
@book{LittkemannHoltupSchulte2006,
  author    = {Littkemann, J. and Holtup, M. and Schulte, K.},
  title     = {Buchf{\"u}hrung: Grundlagen - {\"U}bungen - Klausurvorbereitung},
  publisher = {Gabler},
  address   = {Wiesbaden},
  isbn      = {3409127070},
  year      = {2006},
  language  = {mul}
}
@book{LittkemannHoltupSchulte2012,
  author    = {Littkemann, J. and Holtup, M. and Schulte, K.},
  title     = {Buchf{\"u}hrung: Grundlagen - {\"U}bungen - Klausurvorbereitung},
  edition   = {5. Aufl.},
  publisher = {Gabler},
  address   = {Wiesbaden},
  isbn      = {978-3834934178},
  year      = {2012},
  language  = {mul}
}