Columbia subject headings:
Biology--Costa Rica--Periodicals.
Biology--Tropics--Periodicals.
Conservation of natural resources--Costa Rica--Periodicals.
Conservation of natural resources--Tropics--Periodicals.
Tropical medicine--Costa Rica--Periodicals.
Tropical medicine--Periodicals.
Harvard subject headings:
Tropical medicine--Periodicals
Princeton subject headings:
Periodicals.
Tropical medicine--Periodicals.