Columbia subject headings:
Harvard subject headings:
Civilization, Modern--19th century
Civilization, Modern--20th century
Europe--History--1871-1918.
Europe--History--1918-1945.
World politics--1900-1945
World politics--19th century
Princeton subject headings:
Civilization, Modern--19th century.
Civilization, Modern--20th century.
Europe--History--1871-1918.
Europe--History--1918-1945.
World politics--1900-1945.
World politics--19th century.