Columbia subject headings:
Mexico--Commerce--United States.
Trucking--Mexico--Safety measures.
Trucking--United States--Safety measures.
Trucks--Standards--Mexico--Evaluation.
United States--Commerce--Mexico.
Harvard subject headings:
Mexico--Commerce--United States.
Trucking--Mexico--Safety measures.
Trucking--United States--Safety measures
Trucks--Standards--Mexico--Evaluation.
United States--Commerce--Mexico.
Princeton subject headings: