Columbia subject headings:
Iron industry and trade--Europe--Early works to 1800.
Iron--Metallurgy--Early works to 1800.
Steel industry and trade--Europe--Early works to 1800.
Steel--Metallurgy--Early works to 1800.
Harvard subject headings:
Iron industry and trade--Europe--Early works to 1800.
Iron--Metallurgy--Early works to 1800.
Steel industry and trade--Europe--Early works to 1800.
Steel--Metallurgy--Early works to 1800.
Princeton subject headings:
Iron industry and trade--Europe--Early works to 1800.
Iron--Metallurgy--Early works to 1800.
Steel industry and trade--Europe--Early works to 1800.
Steel--Metallurgy--Early works to 1800.