@book { CustomerRelationshipManagementbeiKreditinstituten,
    title = "Customer Relationship Management bei Kreditinstituten",
    author = "Philipp {Eisele}",
    year = "2002",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832459062",
    url = "https://m.diplom.de/document/221359"
}