@book { WackelzahnPubertt,
    title = "Wackelzahn-Pubertät",
    subtitle = "Gelassen durch die 6-Jahres-Phase. Der praktische Elternratgeber.",
    author = "Laura {Fröhlich}",
    year = "2020",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/535899"
}