Columbia subject headings:
Harvard subject headings:
Greece--Commerce.
Greece--Economic conditions--1918-1974.
Greece--Economic conditions--1974-
Merchant marine--Greece--History--20th century.
Shipping--Greece--History--20th century.
Princeton subject headings:
Greece--Commerce.
Greece--Economic conditions--1918-1974.
Greece--Economic conditions--1974-.
Merchant marine--Greece--History--20th century.
Shipping--Greece--History--20th century.