@book { TheroleofCRMwithincorporatestrategy,
    title = "The role of CRM within corporate strategy",
    subtitle = "A general analysis",
    author = "Jörg {Pfeiffenbrück}",
    year = "2005",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832440664",
    url = "https://m.diplom.de/document/219695"
}