Columbia subject headings:
Harvard subject headings:
Hydraulic engineering--China--Pingluo Xian--History.
Pingluo Xian (China)--History.
Water resources development--China--Pingluo Xian--History.
Princeton subject headings:
Hydraulic engineering--China--Pingluo Xian--History.
Water resources development--China--Pingluo Xian--History.