Columbia subject headings:
Technology--Spain--Castile--History.
Harvard subject headings:
Power resources--Spain--Castile--History--16th century.
Power resources--Spain--Castile--History--17th century.
Technology--Spain--Castile--History--16th century.
Technology--Spain--Castile--History--17th century.
Princeton subject headings:
Science--Spain--Castile--History.
Science--Spain--Castile--Social aspects.
Technological innovations--Spain--Castile.
Technology--Spain--Castile--History.
Technology--Spain--Castile--Social aspects.