Columbia subject headings:
Grain trade--History--20th century.
Merchant marine--Finland--Åland--History.
Sailing ships--Finland--Åland--History.
Åland (Finland)--Economic conditions.
Harvard subject headings:
Gustaf Erikson (Firm)
Merchant ships--Finland--History.
Sailing ships
Shipping--Finland--Åland--History.
Princeton subject headings:
Åland (Finland)--Economic conditions.
Grain trade--History--20th century.
Merchant marine--Finland--Åland--History.
Sailing ships--Finland--Åland--History.