Columbia subject headings:
Jerusalem--History--Latin Kingdom, 1099-1244--Early works to 1800.
Naples (Kingdom)--History--Early works to 1800.
Sicily (Italy)--History--Early works to 1800.
Harvard subject headings:
Crusades
Jerusalem--History--Latin Kingdom, 1099-1244--Early works to 1800.
Naples (Kingdom)--History--Early works to 1800.
Sicily (Italy)--History--Early works to 1800.
Princeton subject headings: