@book { GesundheitsratgeberketoveganeErnhrung,
    title = "Gesundheitsratgeber keto-vegane Ernährung",
    author = "Karina {Haufe}",
    year = "2021",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/993664"
}