@book { GrundwissenProduktion,
    title = "Grundwissen Produktion",
    subtitle = "Produktions- und Kostentheorie",
    author = "Bernd {Rieper} and Thomas {Witte}",
    year = "2005",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1099003"
}