Columbia subject headings:
Feudal law--Baltic States.
Merkel, Garlieb Helvig, 1769-1850.
Political science--Latvia--History.
Harvard subject headings:
Latvia--History.
Merkel, Garlieb, 1769-1850.
Serfdom--Latvia.
Princeton subject headings:
Latvia--History.
Merkel, Garlieb, 1769-1850.
Serfdom--Latvia.