Columbia subject headings:
Harvard subject headings:
Balkan Peninsula--History--1918-1945--Congresses.
Europe, Central--History--20th century--Congresses.
Europe, Eastern--History--1918-1945--Congresses.
Princeton subject headings:
Balkan Peninsula--History--1918-1945.
Europe, Central--History--20th century.
Europe, Eastern--History--1918-1945.