Columbia subject headings:
Europe--Civilization.
Europe--History--476-1492.
Spain--Civilization.
Spain--History--711-1516.
Harvard subject headings:
Feudalism--Social aspects--Europe--History.
Feudalism--Social aspects--Spain--History.
Middle class--Europe--History.
Middle class--Spain--History.
Social change--Europe--History.
Social change--Spain--History.
Princeton subject headings: