@book { GenerationSmartphone,
    title = "Generation Smartphone",
    subtitle = "Digitalisierung des stationären Handels mittels Smartphone",
    author = "Milan {Freudenberg}",
    year = "2016",
    publisher = "Diplom.de",
    address = "Hamburg, Germany",
    url = "https://m.diplom.de/document/334918"
}