Columbia subject headings:
Mediterranean Region--Commerce--Congresses.
Merchants--Mediterranean Region--History--Congresses.
Harvard subject headings:
Mediterranean Region--Commerce--Congresses.
Mediterranean Region--Commerce--History--Congresses.
Merchants--Mediterranean Region--History--Congresses.
Shipping--Mediterranean Region--History--Congresses.
Trade routes--Mediterranean Region--History--Congresses.
Princeton subject headings:
Mediterranean Region--Commerce--Congresses.
Merchants--Mediterranean Region--History--Congresses.