@book { Das5MinutenImmunprogramm,
    title = "Das 5-Minuten-Immunprogramm",
    author = "Manuel {Eckardt}",
    year = "2022",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/1182388"
}