@book { AlternativeWerbung,
    title = "Alternative Werbung",
    subtitle = "Möglichkeiten und Grenzen des 'Viral Marketing' am Beispiel der iMakler GmbH",
    author = "Sabine {Müller}",
    year = "2009",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836629461",
    url = "https://m.diplom.de/document/226780"
}