@book { PersnlicheBeratungversusOnlineBeratung,
    title = "Persönliche Beratung versus Online Beratung",
    author = "André {Preuninger}",
    year = "2010",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783842802759",
    url = "https://m.diplom.de/document/227960"
}