Columbia subject headings:
Harvard subject headings:
Gaeta (Italy)--History--Siege, 1860-1861--Congresses.
Kingdom of the Two Sicilies--History--1848-1861--Congresses.
Princeton subject headings:
Gaeta (Italy)--History--Siege, 1860-1861--Congresses.
Naples (Kingdom)--History--1848-1861--Congresses.