Columbia subject headings:
Harvard subject headings:
Christianity--Europe, Central--History--Congresses.
Church and state--Europe, Central--History--Congresses.
Church and state--Europe, Eastern--History--20th century--Congresses.
Church and state--Soviet Union--History--Congresses.
Communism and religion--Congresses.
Communism and religion--Europe, Central--History--Congresses.
Europe, Central--Church history--Congresses.
Europe, Eastern--Church history--20th century--Congresses.
National socialism and religion--Congresses.
Soviet Union--Church history--Congresses.
Princeton subject headings:
Christianity--Europe, Central--History--Congresses.
Church and state--Europe, Central--History--Congresses.
Communism and religion--Europe, Central--History--Congresses.
Europe, Central--Church history--Congresses.