Columbia subject headings:
Harvard subject headings:
Balkan Peninsula--Politics and government
Danube River
Eastern question (Balkan)
Europe--Politics and government--1914-
Europe--Politics and government--1918-1945
Germany--Foreign relations--1933-
Germany--Foreign relations--1933-1945
Little Entente
Pangermanism
Princeton subject headings:
Balkan Peninsula--Politics and government.
Danube River.
Eastern question (Balkan)
Europe--Politics and government--1914-.
Germany--Foreign relations--1933-.
Little Entente
Pangermanism.