@book { AufbaueinesumfassendenQualittsmanagements,
    title = "Aufbau eines umfassenden Qualitätsmanagements",
    author = "Klaus {Harder}",
    year = "1997",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832404901",
    url = "https://m.diplom.de/document/216208"
}