Columbia subject headings:
Environmental policy--Spain--País Vasco--History--20th century.
Environmentalism--Spain--País Vasco--History--20th century.
Nationalism--Spain--País Vasco--History--20th century.
Harvard subject headings:
Environmental policy--Spain--País Vasco--Citizen participation--History--20th century.
Environmentalism--Spain--País Vasco--History--20th century.
Nationalism--Spain--País Vasco--History--20th century
Princeton subject headings:
Environmental policy--Spain--País Vasco--History--20th century.
Environmentalism--Spain--País Vasco--History--20th century.
Nationalism--Spain--País Vasco--History--20th century.