Columbia subject headings:
Harvard subject headings:
Education and state--Germany--History--20th century.
Education--Germany--History--20th century
Educational change--Germany--History--20th century
Ganztagsschulen--Germany--History--20th century.
School day--Germany--History--20th century.
Princeton subject headings:
Educational change--Germany (West)--History.
Ganztagsschulen--Germany (West)--History.
School day--Germany (West)--History.