Columbia subject headings:
Middle class--Political activity--Germany--Prussia.
Social conflict.
Upper class--Political activity--Germany--Prussia.
Harvard subject headings:
Middle class--Germany--Prussia--Political activity.
Middle class--Political activity--Germany--Prussia.
Social conflict.
Upper class--Germany--Prussia--Political activity.
Upper class--Political activity--Germany--Prussia.
Princeton subject headings:
Middle class--Germany--Prussia--Political activity.
Social conflict.
Upper class--Germany--Prussia--Political activity.