Columbia subject headings:
Drug control.
Drug traffic--Mexico--History--20th century.
Drug traffic--United States--History--20th century.
Mexico--Foreign relations--United States.
United States--Foreign relations--Mexico.
Harvard subject headings:
Drug control--Mexico--History--20th century.
Drug control--United States--History--20th century.
Drug traffic--Mexico--History--20th century.
Princeton subject headings:
Drug control--Mexico--History--20th century.
Drug control--United States--History--20th century.
Drug traffic--Mexico--History--20th century.