Columbia subject headings:
Ecumenical movement--History.
Europe--Politics and government--1918-1945.
European cooperation.
Harvard subject headings:
Christianity and international relations--History--20th century.
Church and state--Europe--History--20th century.
Ecumenical movement--History.
Europe--Politics and government--1918-1945.
European cooperation.
European federation--History
Princeton subject headings:
Christianity and international relations--History--20th century.
Church and state--Europe--History--20th century.
Ecumenical movement--History.
European federation--History.