4Sadahiko, Kano.Technical Innovations, Standardizafion and Regional Comparison:A Case Studyin Mobile Communications.Telecommunication Policy,2000, (24):305-321.
7M.Greenstein,Shane.lnvisible Hand versus Invisible Advisors:Coordination Mechanisms in Economic Net- works. Public Access and Closed Network Membership, 1994,(8):135-160.
8Katz,Shapiro.Systems competition and network effects. Journal of Economic Perspectives,1994,8 (8):93-116.