Columbia subject headings:
Industries--United States--Classification.
Manufactures--Classification.
Mineral industries--Classification.
Mineral industries--United States--Classification.
Harvard subject headings:
Manufactures--Classification.
Manufactures--United States--Classification.
Manufacturing industries--Classification.
Manufacturing industries--United States--Classification.
Mineral industries--Classification.
Mineral industries--United States--Classification.
Princeton subject headings:
Manufacturing industries--Classification.
Manufacturing industries--United States--Classification.
Mineral industries--Classification.
Mineral industries--United States--Classification.