Columbia subject headings:
Harvard subject headings:
History--Philosophy--Congresses
Küttler, Wolfgang--Congresses.
Revolutions--History--Congresses.
Social change--Congresses
Princeton subject headings:
History--Philosophy--Congresses.
Küttler, Wolfgang--Congresses.
Political science--Germany--Congresses.
Revolutions--History--Congresses.
Social change--Congresses.