Columbia subject headings:
Kurli︠a︡ndskai︠a︡ gubernīi︠a︡ (Russia)--Economic conditions.
Kurli︠a︡ndskai︠a︡ gubernīi︠a︡ (Russia)--History.
Harvard subject headings:
Courland (Duchy)--Economic conditions.
Courland (Duchy)--History.
Princeton subject headings: