Columbia subject headings:
Amazonas (Brazil)--Economic conditions.
Amazonas (Brazil)--History.
Amazonas (Brazil)--Social life and customs.
Harvard subject headings:
Amazonas (Brazil)--Economic conditions.
Amazonas (Brazil)--History.
Amazonas (Brazil)--Social life and customs.
Princeton subject headings:
Amazonas (Brazil)--Economic conditions.
Amazonas (Brazil)--History.
Amazonas (Brazil)--Social life and customs.