Columbia subject headings:
Industrial revolution.
Patent laws and legislation--Germany--History--19th century.
Patent laws and legislation--Germany--History--20th century.
Patent laws and legislation--History--19th century.
Patent laws and legislation--History--20th century.
Harvard subject headings:
Patent laws and legislation--Germany--History.
Patent laws and legislation--History.
Princeton subject headings:
Industrial revolution--Europe--History.
Patent laws and legislation--Germany.