2[4]Isaksen A: Regional Clusters between Local and Non-local Relation ( A Comparative European Study), Paper for IGU Conference, Turion 10~14 July 2001
3[5]David B.Audretach and Maryann P.Feldman R&D Spillovers and the Geography of Innovation and Production AER,1996(6)
4[6]Michael Albu:Technological Learning and Innovation in Industrial Clusters in the South,SPRU,Electronic Working Papers Series,Paper No 7,1997