@book { UntersttzungsmanagementimAlter,
    title = "Unterstützungsmanagement im Alter",
    author = "Olaf {Wessels}",
    year = "2004",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832476953",
    url = "https://m.diplom.de/document/222961"
}