Columbia subject headings:
Trucking--Government policy--United States--History.
Trucking--Law and legislation--United States--History.
Trucking--United States--History.
Harvard subject headings:
Trucking--Government policy--United States--History.
Trucking--Law and legislation--United States--History.
Trucking--United States--History.
Princeton subject headings:
Trucking--Government policy--United States--History.
Trucking--Law and legislation--United States--History.
Trucking--United States--History.