@book { KundenbindunginGenossenschaftsbanken,
    title = "Kundenbindung in Genossenschaftsbanken",
    subtitle = "Eine kritische Analyse",
    author = "Christian H. {Volmer}",
    year = "2008",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836607858",
    url = "https://m.diplom.de/document/229069"
}