Columbia subject headings:
Harvard subject headings:
Crusades--13th-15th centuries
Italy--History--476-1492.
Naples (Kingdom)--History--1016-1268.
Naples (Kingdom)--History--Anjou dynasty, 1268-1442.
Papacy--History--1309-1378
Papacy--History--To 1309
Sicily (Italy)--History--1194-1282
Sicily (Italy)--History--1282-1409
Princeton subject headings:
Crusades--13th-15th centuries.
Italy--History--476-1492.
Papacy--History--1309-1378.
Papacy--History--To 1309.