Columbia subject headings:
Mafia--Italy--Monreale--History--19th century.
Organized crime--Italy--Monreale--History--19th century.
Secret societies--Italy--Monreale--History--19th century.
Harvard subject headings:
Mafia--Italy--Monreale--History--19th century.
Organized crime--Italy--Monreale--History--19th century.
Secret societies--Italy--Monreale--History--19th century.
Princeton subject headings:
Mafia--Italy--History.
Secret societies--Italy--History.