Columbia subject headings:
Harvard subject headings:
Europe--Civilization--18th century.
Europe--Civilization--19th century.
Europe--Civilization--20th century.
Germany--Foreign relations--United States.
North America--Civilization
United States--Foreign relations--Germany.
Princeton subject headings:
Europe--Civilization--18th century.
Europe--Civilization--19th century.
Europe--Civilization--20th century.
North America--Civilization.