Columbia subject headings:
Belgium--Foreign relations--1914-1951.
Belgium--Foreign relations--Germany.
Germany--Foreign relations--1933-1945.
Germany--Foreign relations--Belgium.
Harvard subject headings:
Belgium--Foreign relations--1914-1951.
Belgium--Foreign relations--Germany.
Germany--Foreign relations--1933-1945.
Germany--Foreign relations--Belgium.
Princeton subject headings:
Belgium--Foreign relations--1914-1951.
Belgium--Foreign relations--Germany.
Germany--Foreign relations--1933-1945.
Germany--Foreign relations--Belgium.