Columbia subject headings:
Harvard subject headings:
Drug control--Spain--País Vasco--History--20th century.
Drug traffic--Spain--País Vasco--History--20th century.
ETA (Organization)--History--20th century.
Heroin industry--Spain--País Vasco--History--20th century.
Princeton subject headings:
Drug traffic--Spain--País Vasco--History--20th century.
ETA (Organization)
Heroin industry--Spain--País Vasco--History--20th century.