Columbia subject headings:
Ereğli Demir-Çelik (Firm)
Iron industry and trade--Turkey--Ereğli (Zonguldak İli)
Steel industry and trade--Turkey--Ereğli (Zonguldak İli)
Harvard subject headings:
Ereğli (Zonguldak İli, Turkey)--Economic conditions--20th century.
Iron industry and trade--Turkey--Ereğli (Zonguldak İli)--History--20th century.
Steel industry and trade--Turkey--Ereğli (Zonguldak İli)--History--20th century.
Princeton subject headings:
Ereğli Demir-Çelik (Firm)
Iron industry and trade--Turkey--Ereğli (Zonguldak İli).
Steel industry and trade--Turkey--Ereğli (Zonguldak İli).