Columbia subject headings:
Gussstahlfabrik Fried. Krupp (Essen, Germany)
Krupp family.
Ordnance--Manufacture.
Harvard subject headings:
Krupp family.
Krupp'sche Gussstahlfabrik (Essen, Germany)
Ordnance--Manufacture
Steel-works--Germany--Essen--History.
Steel-works--History.
Princeton subject headings: