@book { VertriebswegefrWebinarundWebconferencingsysteme,
    title = "Vertriebswege für Webinar- und Webconferencingsysteme",
    author = "Karim {Rabah}",
    year = "2018",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    url = "https://m.diplom.de/document/442319"
}