@book { DerFibromyalgieRatgeber,
    title = "Der Fibromyalgie-Ratgeber",
    author = "Holger {Westermann} and  {Deutsche Fibromyalgie Vereinigung e.V}",
    year = "2022",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403112"
}