Ernie Chan Robert A. van de Geijn William Gropp Rajeev Thakur Collective communication on architectures that support simultaneous communication over multiple links. 2-11 2006 conf/ppopp/2006 PPOPP http://doi.acm.org/10.1145/1122971.1122975 db/conf/ppopp/ppopp2006.html#ChanGGT06