Columbia subject headings:
Indians of South America--Amazon River Valley--Languages--Congresses.
Indians of South America--Languages--Congresses.
Harvard subject headings:
Indians of South America--Amazon River Valley--Languages--Congresses.
Indians of South America--Languages--Congresses.
Princeton subject headings:
Indians of South America--Amazon River Valley--Languages--Congresses.
Indians of South America--Languages--Congresses.