Columbia subject headings:
Llanos (Colombia and Venezuela)--Description and travel.
Natural history--Orinoco River (Venezuela and Colombia)
Orinoco River (Venezuela and Colombia)--Description and travel.
Harvard subject headings:
Llanos (Colombia and Venezuela)--Description and travel.
Natural history--Orinoco River (Venezuela and Colombia).
Orinoco River (Venezuela and Colombia)--Description and travel.
Princeton subject headings: