@book { VorwortinASNeillSummerhill,
    title = "Vorwort in A. S. Neill „Summerhill“",
    author = "Erich {Fromm} and Rainer {Funk}",
    year = "2016",
    publisher = "Edition Erich Fromm",
    address = "München, Deutschland",
    url = "https://books.openpublishing.com/document/313994"
}