Columbia subject headings:
Border patrols--Mexican-American Border Region.
Drug control--Mexican-American Border Region.
Drug traffic--Mexican-American Border Region.
Harvard subject headings:
Border patrols--Mexican-American Border Region.
Drug control--Mexican-American Border Region
Drug traffic--Mexican-American Border Region
Princeton subject headings:
Border patrols--Mexican-American Border Region.
Drug control--Mexican-American Border Region.
Drug traffic--Mexican-American Border Region.