@book { Marketing,
    title = "Marketing",
    subtitle = "Grundlagen und Managementprozess",
    author = "Arnold {Hermanns} and Stephanie C. {Kiendl} and Pascal C. van {Overloop}",
    year = "2012",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1220827"
}