Columbia subject headings:
Harvard subject headings:
North Rhine-Westphalia (Germany)--History.
North Rhine-Westphalia (Germany)--Social conditions.
Princeton subject headings:
North Rhine-Westphalia (Germany)
North Rhine-Westphalia (Germany)--Intellectual life.
North Rhine-Westphalia (Germany)--Politics and government--History.
Westphalia (Germany)--History.
Westphalia (Germany)--Intellectual life.
Westphalia (Germany)--Politics and government--History.