@book { SchwangerschaftGeburtStillzeit,
    title = "Schwangerschaft, Geburt & Stillzeit",
    author = "Elke {Mattern} and Angela {Schweer}",
    year = "2011",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403351"
}