@book{Hufnagel2011,
  author    = {Hufnagel, W.},
  title     = {Management unterst{\"u}tztes Controlling, LE1 - LE 4},
  address   = {M{\"u}nster},
  year      = {2011},
  language  = {mul}
}
@book{ZiegenbeinWalter2011,
  author    = {Ziegenbein, R. and Walter, J.},
  title     = {Transatlantische Internationalisierung von kleinen und mittleren Unternehmen - Implikationen und Konzeptans{\"a}tze},
  address   = {Dortmund/M{\"u}nster},
  year      = {2011},
  language  = {de}
}
@book{Toennissen2011,
  author    = {T{\"o}nnissen, Stefan},
  title     = {Revision der IT-Governance mit CoBiT : Leitfaden f{\"u}r die Pr{\"u}fungspraxis},
  publisher = {Erich Schmidt Verlag},
  address   = {Berlin},
  isbn      = {978-3-503-13012-2},
  publisher      = {FH M{\"u}nster - University of Applied Sciences},
  pages     = {323},
  year      = {2011},
  language  = {de}
}