@book { MarketingControlling,
    title = "Marketing-Controlling",
    subtitle = "Systeme und Methoden für mehr Markt- und Unternehmenserfolg",
    author = "Jörg {Link} and Christoph {Weiser}",
    year = "2014",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1220791"
}