Columbia subject headings:
Harvard subject headings:
Pingshan Xian (Hebei Sheng, China)--Economic conditions.
Pingshan Xian (Hebei Sheng, China)--Social conditions.
Princeton subject headings:
Pingshan Xian (Hebei Sheng, China)--Economic conditions.
Pingshan Xian (Hebei Sheng, China)--Social conditions.