Columbia subject headings:
Civilization, Modern--History.
Communication--History--18th century.
Communication--History--19th century.
Communication--History--20th century.
Harvard subject headings:
Civilization, Modern--History
Communication--History--18th century.
Communication--History--19th century.
Communication--History--20th century.
Princeton subject headings:
Civilization, Modern--History.
Communication--History--18th century.
Communication--History--19th century.
Communication--History--20th century.