@book { MobileMarketingundseineErfolgspotentiale,
    title = "Mobile Marketing und seine Erfolgspotentiale",
    author = "Alexandra {Schmidt}",
    year = "2004",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832478216",
    url = "https://m.diplom.de/document/223081"
}