@book { MglichkeitenundGrenzeneinzelnerInstrumentedeskocontrollings,
    title = "Möglichkeiten und Grenzen einzelner Instrumente des Ökocontrollings",
    author = "Ralf {Boltzen}",
    year = "2004",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832479930",
    url = "https://m.diplom.de/document/223018"
}