@book { GesundeundschmerzfreieFe,
    title = "Gesunde und schmerzfreie Füße",
    author = "Dr. Ursula {Manunzio}",
    year = "2021",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/993652"
}