Columbia subject headings:
Harvard subject headings:
Smoking--Social aspects--Bulgaria--History--19th century.
Smoking--Social aspects--Bulgaria--History--20th century.
Tobacco industry--Bulgaria--History--19th century.
Tobacco industry--Bulgaria--History--20th century.
Princeton subject headings:
Smoking--Social aspects--Bulgaria--History--19th century.
Smoking--Social aspects--Bulgaria--History--20th century.
Tobacco industry--Bulgaria--History--19th century.
Tobacco industry--Bulgaria--History--20th century.