Columbia subject headings:
Harvard subject headings:
Amazon River Valley--Description and travel--Congresses.
Amazon River Valley--Economic conditions--Congresses.
Amazon River Valley--In literature--Congresses.
Amazon River Valley--Politics and government--Congresses.
Amazon River Valley--Social conditions--Congresses.
Ethnology--Amazon River Valley--Congresses.
Princeton subject headings:
Amazon River Valley--Description and travel--Congresses.
Amazon River Valley--Economic conditions--Congresses.
Amazon River Valley--In literature--Congresses.
Amazon River Valley--Politics and government--Congresses.
Amazon River Valley--Social conditions--Congresses.
Ethnology--Amazon River Valley--Congresses.