Columbia subject headings:
Harvard subject headings:
Social participation--Germany--History.
Sports for children--Germany--History.
Voluntarism--Germany--History.
Volunteer workers in recreation--Germany--History.
Young volunteers--Germany--History.
Princeton subject headings:
Social participation--Germany--History.
Sports for children--Germany--History.
Voluntarism--Germany--History.
Volunteer workers in recreation--Germany--History.
Young volunteers--Germany--History.