7Young A. The razor: edge: Distortions and incre- mental reform in the People's Republic of China [ J ]. The Quarterly Journal of Economics, 2000, 115 (4) : 1091 - 1135.
8Seidman S. B. Network structure and minimum degree [ J ]. Social Networks, 1983, (5) ,269 - 287.
9Campbell J: The Relevance of Input - Output Analysis and Digraph Concepts to Growth Pole Theory[ D]. University of Washington, 1970.
10Schnabl H: The Evolution of Production Struc- tures Analyzed by a Multi - Layer Procedure [ J ]. Econom- ic Systems Research, 1994, 6(1) : 51 - 68.