@article{KerkaSchweringStriewe2011,
  author    = {Kerka, Friedrich and Schwering, Markus G. and Striewe, Frank},
  title     = {Innovationsorientierte Marktforschung},
  series = {Pepels, Werner (Hrsg.): Produktmanagement - Digitale Fachbibliothek},
  journal   = {Pepels, Werner (Hrsg.): Produktmanagement - Digitale Fachbibliothek},
  year      = {2011},
  language  = {mul}
}
@incollection{KerkaSchweringStriewe2011,
  author    = {Kerka, Friedrich and Schwering, Markus G. and Striewe, Frank},
  title     = {Innovationsorientierte Marktforschung},
  series = {Pepels, Werner (Hrsg.): Produktmanagement - Digitale Fachbibliothek},
  booktitle = {Pepels, Werner (Hrsg.): Produktmanagement - Digitale Fachbibliothek},
  address   = {D{\"u}sseldorf},
  year      = {2011},
  language  = {mul}
}
@book{Hufnagel2011,
  author    = {Hufnagel, W.},
  title     = {Management unterst{\"u}tztes Controlling, LE1 - LE 4},
  address   = {M{\"u}nster},
  year      = {2011},
  language  = {mul}
}