@book { OnlineMarketingfrBeginnerundStartups8,
    title = "Online Marketing für Beginner und Startups 8",
    author = "Brigitte E.S. {Jansen} and Brigitte E.S. {Jansen} and Roland {Kreische} and Guenter Thomas {Baur} and Bernd {Wobser}",
    year = "2023",
    publisher = "Gesellschaft für Arbeitsmethodik e.V.",
    address = ", Deutschland",
    url = "https://tolino.openpublishing.com/document/1373841"
}