Columbia subject headings:
Natural history--South America.
Scientific expeditions.
South America--Description and travel.
Voyages and travels.
Harvard subject headings:
Natural history--South America
Scientific expeditions
South America--Description and travel.
Voyages and travels
Princeton subject headings:
Humboldt, Alexander von, 1769-1859--Travel--South America.
Natural history--South America.
Scientific expeditions.
South America--Description and travel.
Voyages and travels.