Columbia subject headings:
Harvard subject headings:
Crusades
Merchants--Italy--Tuscany--History--To 1500.
Merchants--Middle East--History--To 1500.
Middle East--Commerce--History--To 1500.
Military history, Medieval
Tuscany (Italy)--Commerce--History--To 1500.
Princeton subject headings:
Italians--Middle East--History--To 1500.
Merchants, Foreign--Middle East--History.
Middle East--Commerce--Italy--Tuscany--History.
Tuscany (Italy)--Commerce--Middle East--History.