Columbia subject headings:
Harvard subject headings:
Postal service--China--History--19th century.
Postal service--China--History--20th century.
Telecommunication--China--History--19th century.
Telecommunication--China--History--20th century.
Princeton subject headings:
Postal service--China--History--19th century.
Postal service--China--History--20th century.
Telecommunication--China--History--19th century.
Telecommunication--China--History--20th century.