@book { Controlling,
    title = "Controlling",
    subtitle = "Grundlagen einer erfolgsorientierten Unternehmenssteuerung",
    author = "Rolf {Brühl}",
    year = "2016",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1221270"
}