Columbia subject headings:
Indians of Mexico--Economic conditions.
Indians of Mexico--Employment--History.
Indians of South America--Economic conditions.
Indians of South America--Employment--History.
Mexico--History.
South America--History.
Harvard subject headings:
Princeton subject headings:
Indians of Mexico--Economic conditions.
Indians of Mexico--Employment--History.
Indians of South America--Economic conditions.
Indians of South America--Employment--History.
Mexico--History.
South America--History.