Columbia subject headings:
Agricultural innovations--Economic aspects--Tropics.
Agriculture and state--Tropics.
Farms, Small--Tropics.
Harvard subject headings:
Agricultural innovations--Economic aspects--Tropics.
Agriculture and state--Tropics.
Farms, Small--Tropics.
Princeton subject headings:
Agricultural innovations--Economic aspects--Tropics.
Agriculture and state--Tropics.
Farms, Small--Tropics.