Columbia subject headings:
Catholic Church--Foreign relations--Europe, Eastern.
Communism and Christianity--Catholic Church--Europe, Eastern.
Europe, Eastern--Church history.
Europe, Eastern--Foreign relations--Catholic Church.
Harvard subject headings:
Catholic Church--Foreign relations--Europe, Eastern.
Communism and Christianity--Catholic Church--Europe, Eastern.
Communism and Christianity--Catholic Church.
Communism and Christianity--Europe, Eastern.
Europe, Eastern--Church history.
Europe, Eastern--Foreign relations--Catholic Church.
Princeton subject headings: