Columbia subject headings:
Balkan Peninsula--Foreign relations--Germany.
Germany--Foreign relations--1918-1933.
Germany--Foreign relations--Balkan Peninsula.
Harvard subject headings:
Balkan Peninsula--Foreign relations--Germany.
Germany--Foreign relations--1918-1933.
Germany--Foreign relations--Balkan Peninsula.
Princeton subject headings:
Europe, Eastern--Commerce--Germany.
Europe, Eastern--Foreign relations--Germany.
Europe, Southern--Commerce--Germany.
Europe, Southern--Foreign relations--Germany.
Germany--Commerce--Europe, Eastern.
Germany--Commerce--Europe, Southern.
Germany--Foreign relations--Europe, Eastern.
Germany--Foreign relations--Europe, Southern.