Columbia subject headings:
Bulgaria--Economic conditions--19th century--Sources.
Bulgaria--Population--History--19th century--Sources.
Land tenure--Bulgaria--History--19th century--Sources.
Taxation--Bulgaria--Lists--History--19th century.
Harvard subject headings:
Bulgaria--Economic conditions--19th century--Sources.
Bulgaria--Population--History--19th century--Sources.
Land tenure--Bulgaria--History--19th century--Sources.
Taxation--Bulgaria--Lists--History--19th century.
Princeton subject headings: