@book { AnsatzfreineMigrationzuVoiceoverIPVoIPCiscoSystemsAVVIDRLsung,
    title = "Ansatz für eine Migration zu Voice over IP (VoIP). Cisco Systems AVVID (R)-Lösung",
    author = "Chris {Jung}",
    year = "2008",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638054782",
    url = "https://www.hausarbeiten.de/document/92336"
}