@book { Unternehmensethik,
    title = "Unternehmensethik",
    subtitle = "Der Weg zur gesellschaftlichen Verantwortung",
    author = "Johannes {Heisig}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832442682",
    url = "https://m.diplom.de/document/219883"
}