@Article{SCI:Ma94a,
  author =    "K.L. Ma and J. Painter and C.D. Hansen and M.
              Krogh",
  title =     "Parallel Volume Rendering Using Binary-Swap
              Compositing",
  journal =   "{IEEE} Computer Graphics and Applications",
  volume =    "14",
  number =    "4",
  pages =     "59--68",
  year =      "1994",
}