Columbia subject headings:
Europe--Foreign relations--1871-1918.
Europe--History--1871-1918.
Europe--Politics and government--1871-1918.
Harvard subject headings:
Europe--Politics and government--1871-1918.
International relations--History--19th century.
International relations--History--20th century
Princeton subject headings:
Europe--Politics and government--1871-1918.
International relations--History--19th century.
International relations--History--20th century.