@book { ValueAddedServicesimPrivatkundengeschftderKreditinstitute,
    title = "Value Added Services im Privatkundengeschäft der Kreditinstitute",
    author = "Thorsten {Lenz}",
    year = "1998",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832411206",
    url = "https://m.diplom.de/document/217010"
}