Ch’ao-Ting Chi 
Key Economic Areas in Chinese History [PDF ebook] 
As Revealed in the Development of Public Works for Water-Control

This book, first published in 1936, offers the conception of the dynamics of the Key Economic Area as an aid to the understanding of Chinese economic history. By tracing their development through a historical study of the construction of irrigation and flood-control works and transport canals, it shows the function of the Key Economic Area as an instrument of control of subordinate areas.