Columbia subject headings:
Agriculture--Italy--Sicily--History.
Feudalism--Italy--Sicily--History.
Sicily (Italy)--Genealogy.
Harvard subject headings:
Estates (Social orders)--Italy--Sicily--History.
Feudalism--Italy--Sicily--History.
Land tenure--Italy--Sicily--History.
Princeton subject headings:
Agriculture--Italy--Sicily--History.
Feudalism--Italy--Sicily--History.
Sicily (Italy)--Genealogy.