@inproceedings{riesen-cug06.pdf,
  author={R. Riesen and C. Vaughan and and Torsten Hoefler},
  title={{What if MPI Collective Operations Were Instantaneous?}},
  institution={Cray Inc.},
  year={2006},
  month={May},
  booktitle={Proceedings of the 2006 Cray User Group Meeting},
  location={Lugano, Switzerland},
}