Columbia subject headings:
Harvard subject headings:
Crusades--13th-15th centuries
Crusades--Participation, Polish.
Europe, Eastern--History--To 1500.
Poland--History--Piast period, 960-1386
Princeton subject headings:
Crusades--13th-15th centuries.
Crusades--Participation, Polish.
Europe, Eastern--History--To 1500.
Poland--History--Piast period, 960-1386.