4Sternitzke C,Bartkowski A,Schramm R.Visualizing Patent Statistics by Means of Social Network Analysis Tools[J].World Patent Information,2008,30(2):115-131.
5Park H,Yoon J.Assessing Coreness and Intermediarity of Technology Sectors Using Patent Co-classification Analysis:the Caseof Korean National R&D[J].Scientometrics,2014,98(2):853-890.