Columbia subject headings:
Employee screening--Law and legislation--United States.
Hazardous substances--Transportation--Law and legislation--United States.
Hazardous substances--Transportation--Security measures--United States.
Truck drivers--Licenses--United States.
Harvard subject headings:
Employee screening--Law and legislation--United States.
Hazardous substances--Transportation--Law and legislation--United States.
Hazardous substances--Transportation--Security measures--United States.
Truck drivers--Licenses--United States.
Princeton subject headings:
Employee screening--Law and legislation--United States.
Hazardous substances--Transportation--Law and legislation--United States.
Hazardous substances--Transportation--Security measures--United States.
Truck drivers--Licenses--United States.