Columbia subject headings:
Communication--Social aspects--Europe.
Postal service--Europe--History--18th century.
Written communication--Europe--History--18th century.
Harvard subject headings:
Communication--Social aspects--Europe.
Postal service--Europe--History--18th century.
Written communication--Europe--History--18th century.
Princeton subject headings:
Communication--Social aspects--Europe.
Postal service--Europe--History--18th century.
Written communication--Europe--History--18th century.