Network collection from M. Newman                                          
http://www-personal.umich.edu/~mejn/netdata/                               
                                                                           
The graph cond-mat-2003 contains an updated version of cond-mat, the       
collaboration network of scientists posting preprints on the condensed     
matter archive at www.arxiv.org.  This version is based on preprints posted
to the archive between January 1, 1995 and June 30, 2003.  The largest     
component of this network, which contains 27519 scientists, has been used  
by several authors as a test-bed for community-finding algorithms for large
networks; see for example J. Duch and A. Arenas, Phys. Rev. E 72, 027104   
(2005).  The network is weighted, with weights assigned as described in    
M. E. J. Newman, Phys. Rev. E 64, 016132 (2001).                           
                                                                           
These data can be cited as either of:                                      
                                                                           
  M. E. J. Newman, The structure of scientific collaboration networks,     
  Proc. Natl. Acad. Sci. USA 98, 404-409 (2001).  This paper describes the 
  original 1999 version of the network.                                    
                                                                           
  M. E. J. Newman, Fast algorithm for detecting community structure in     
  networks, Phys. Rev. E 69, 066133 (2004).  This paper describes the 2003 
  version.