Columbia subject headings:
Harvard subject headings:
Agricultural industries--China--Qinghai Sheng--History.
Natural disasters--China--Qinghai Sheng--History.
Qinghai Sheng (China)--Economic conditions.
Princeton subject headings:
Agricultural industries--China--Qinghai Sheng--History.
Natural disasters--China--Qinghai Sheng--History.
Qinghai Sheng (China)--Economic conditions.