@book { DerUmweltberichtalsinternesundexternesMarketingInstrument,
    title = "Der Umweltbericht als internes und externes Marketing-Instrument",
    author = "Thorsten {Rehaag}",
    year = "1998",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832407018",
    url = "https://m.diplom.de/document/216628"
}