Columbia subject headings:
Amazon River Valley--Economic conditions.
Amazon River Valley--Social conditions.
Napo River Valley (Ecuador and Peru)--Economic conditions.
Napo River Valley (Ecuador and Peru)--Social conditions.
Villages--Amazon River Valley.
Villages--Napo River Valley (Ecuador and Peru)
Harvard subject headings:
Amazon River Valley--Economic conditions.
Amazon River Valley--Social conditions.
Napo River Valley (Ecuador and Peru)--Economic conditions.
Napo River Valley (Ecuador and Peru)--Social conditions.
Villages--Amazon River Valley.
Villages--Napo River Valley (Ecuador and Peru)
Princeton subject headings:
Amazon River Valley--Economic conditions.
Amazon River Valley--Social conditions.
Napo River Valley (Ecuador and Peru)--Economic conditions.
Napo River Valley (Ecuador and Peru)--Social conditions.
Villages--Amazon River Valley.
Villages--Napo Valley, Ecuador and Peru.