Columbia subject headings:
Harvard subject headings:
Europe--Politics and government--1871-1918.
Europe--Politics and government--20th century.
Great powers.
World politics--19th century
World politics--20th century
Princeton subject headings:
Europe--Politics and government--1871-1918.
Europe--Politics and government--20th century.
Great powers.
World politics--19th century.
World politics--20th century.