@book { SMSKommunikationin160Zeichen,
    title = "SMS - Kommunikation in 160 Zeichen",
    author = "Arne {Marquardt}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832487911",
    url = "https://m.diplom.de/document/223971"
}