Christian Bird Earl T. Barr Andre Nash Premkumar T. Devanbu Vladimir Filkov Zhendong Su Structure and Dynamics of Research Collaboration in Computer Science. 826-837 2009 SDM http://www.siam.org/proceedings/datamining/2009/dm09_075_birdc.pdf conf/sdm/2009 db/conf/sdm/sdm2009.html#BirdBN09