Columbia subject headings:
Harvard subject headings:
Fried. Krupp AG--History.
Krupp family.
Krupp'sche Gussstahlfabrik (Essen, Germany)--History.
Krupp, Alfred, 1812-1887.
Steel industry and trade--Germany--Essen--History.
Princeton subject headings:
Fried. Krupp AG.
Krupp family.