@book { KundenbindungundKundenbindungsmanagement,
    title = "Kundenbindung und Kundenbindungsmanagement",
    author = "Simon {Becker}",
    year = "2006",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832493769",
    url = "https://m.diplom.de/document/224512"
}