Columbia subject headings:
Agricultural productivity--China--Ningxia Huizu Zizhiqu.
Agriculture--Economic aspects--China--Ningxia Huizu Zizhiqu.
Agriculture--Environmental aspects--China--Ningxia Huizu Zizhiqu.
Farms, Small--China--Ningxia Huizu Zizhiqu.
Harvard subject headings:
Agricultural productivity--China--Ningxia Huizu Zizhiqu.
Agriculture--Economic aspects--China--Ningxia Huizu Zizhiqu.
Agriculture--Environmental aspects--China--Ningxia Huizu Zizhiqu.
Farms, Small--China--Ningxia Huizu Zizhiqu.
Princeton subject headings: