Columbia subject headings:
Harvard subject headings:
Government monopolies--China.
Huan, Kan, 1st cent B.C. Yan tie lun.
Iron industry and trade--China
Salt industry and trade--China
Princeton subject headings:
Government monopolies--China--Early works to 1800.
Huan, Kuan, active 1st century B.C. Yan tie lun.
Iron industry and trade--Government policy--China--Early works to 1800.
Salt industry and trade--Government policy--China--Early works to 1800.