@book { DierichtigeErnhrungbeiMultiplerSklerose,
    title = "Die richtige Ernährung bei Multipler Sklerose",
    author = "Julia {Bierenfeld}",
    year = "2023",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/1319881"
}