12. The computer-readable storage medium of claim 11 wherein the identifying of author clusters includes: generating a publication vector for each author, a publication vector identifying papers authored by the author; and clustering the authors based on distance between the publication vectors.
13. The computer-readable storage medium of claim 12 wherein the distance is defined as follows: 
 Dist( A,B )=1−inner( A,B )/min(| A| 2 ,|B| 2) where inner( )is the dot product and |.| is the norm.