@Book{Ackermann.2004,
  author = {Ackermann, Ingmar},
  title  = {Supply Chain Management in der Automobilindustrie},

  year   = {2004},
  number = {},
  url    = {http://www.gbv.de/dms/zbw/394642848.pdf},

  const  = {\ text}
}
@Book{Hermesch.2002,
  author = {Hermesch, Martin},
  title  = {Die Gestaltung von Interorganisationsbeziehungen:  Theoretische sowie empirische Analysen und Erklärungen},

  year   = {2002},
  number = {},
  url    = {},

  const  = {\ text}
}