第一篇：Interpretation of two-region model parameters  

J. W. Griffioen     D. A. Barry

WATER RESOURCES RESEARCH, VOL. 34, NO. 3, PP. 373-384, 1998
链接：http://www.agu.org/pubs/crossref/1998/97WR02027.shtml

第二篇  Innovation, spillovers and university–industry collaboration: an extended knowledge production function approach
链接：http://joeg.oxfordjournals.org/content/10/2/231.full.pdf+html