@book { InnovationsmarktVoiceoverIPAnalyseundChancen,
    title = "Innovationsmarkt Voice over IP - Analyse und Chancen",
    author = "Barbara {Jung}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832490317",
    url = "https://m.diplom.de/document/224190"
}