Columbia subject headings:
Harvard subject headings:
Austria--Foreign relations--Balkan Peninsula--Congresses.
Balkan Peninsula--Foreign relations--Austria--Congresses.
World War, 1914-1918--Balkan Peninsula--Congresses.
World War, 1914-1918--Diplomatic history--Congresses.
Princeton subject headings:
Austria--Foreign relations--Balkan Peninsula.
Balkan Peninsula--Foreign relations--Austria.
World War, 1914-1918--Balkan Peninsula.
World War, 1914-1918--Diplomatic history.