@book { BankmarketingausinstitutionenkonomischerSicht,
    title = "Bankmarketing aus institutionenökonomischer Sicht",
    author = "Mila {Spiegel}",
    year = "2001",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832447977",
    url = "https://m.diplom.de/document/220385"
}