Mohamad Chaarawi Edgar Gabriel Evaluating Sparse Data Storage Techniques for MPI Groups and Communicators. 297-306 2008 ICCS (1) http://dx.doi.org/10.1007/978-3-540-69384-0_35 conf/iccS/2008-1 db/conf/iccS/iccS2008-1.html#ChaarawiG08