Columbia subject headings:
Harvard subject headings:
Baden-Württemberg (Germany)--History--Congresses.
Pessimism--Congresses.
Progress x Psychological aspects--Congresses.
Social change--Psychological aspects--Congresses.
Princeton subject headings:
Baden-Württemberg (Germany)--History--Congresses.
Pessimism--Congresses.
Progress x Psychological aspects--Congresses.
Social change--Psychological aspects--Congresses.