@book { StressfreieGrundschuljahre,
    title = "Stressfreie Grundschuljahre",
    author = "Doris {Heueck-Mauß}",
    year = "2015",
    publisher = "humboldt",
    address = "Hannover, Deutschland",
    url = "https://schluetersche.openpublishing.com/document/403333"
}