8Petersen M A, Rajan R G. The benefits of lending rela- tionships: Evidence from small business data [ J. The Journal of Finance, 1994, 49( 1 ) : 3 -37.
9Berger A N, Udell G F. Small business credit availability and relationship lending: The importance of bank organi- zational structure [J]. Economic Journal, 2002, 112 (477) : 32 -53.
10Berger A N, Udell G F. A more complete conceptual framework for financing of small and medium enterprises [ R ]. World Bank Policy Research Working Paper, 2005.