@book { TarifpolitikimKreditgewerbe,
    title = "Tarifpolitik im Kreditgewerbe",
    author = "Stefan {Sopp}",
    year = "1997",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832402679",
    url = "https://m.diplom.de/document/216254"
}