Columbia subject headings:
Harvard subject headings:
Europe--History--1789-1900.
Europe--History--20th century.
Europe--Social conditions--1789-1900.
Europe--Social conditions--20th century.
Princeton subject headings:
Political violence.
Revolutions--Europe--History--18th century.
Revolutions--Europe--History--19th century.
Revolutions--Europe--History--20th century.
Social history.
War and society.