Columbia subject headings:
Food supply--Europe--History--Congresses.
Food--Transportation--History--Congresses.
Produce trade--Europe--History--Congresses.
Shipping--Europe--History--Congresses.
Harvard subject headings:
Food supply--Europe--History--Congresses.
Food--Transportation--History--Congresses.
Produce trade--Europe--History--Congresses.
Shipping--Europe--History--Congresses.
Princeton subject headings:
Food supply--Europe--History.
Produce trade--Europe--History.
Shipping--Europe--History.