Columbia subject headings:
Europe--Economic integration--History.
European Union--History.
European federation--History.
Harvard subject headings:
Europe--Economic integration.
Europe--Foreign economic relations--Germany.
Europe--Foreign economic relations.
Europe--History--20th century.
Europe--History--21st century.
European Union
European federation
Germany--Foreign economic relations--Europe.
Princeton subject headings:
Europe--Economic integration--History.
European Union countries--History.
European Union--History.
European communities--History.
European federation--History.