Columbia subject headings:
Llanos (Colombia and Venezuela)--Description and travel.
Llanos (Colombia and Venezuela)--History.
Natural history--Llanos (Colombia and Venezuela)
Nature--Effect of human beings on--Llanos (Colombia and Venezuela)
Orinoco River Region (Venezuela and Colombia)--Description and travel.
Harvard subject headings:
Biogeography--Orinoco River Watershed (Venezuela and Colombia)
Human ecology--Orinoco River Watershed (Venezuela and Colombia)
Princeton subject headings:
Llanos (Colombia and Venezuela)--Description and travel.
Llanos (Colombia and Venezuela)--History.
Natural history--Llanos (Colombia and Venezuela).
Nature--Effect of human beings on--Llanos (Colombia and Venezuela).
Orinoco River Region (Venezuela and Colombia)--Description and travel.