@Article{cga04-hopf,
  author = {Hopf, M. and Luttenberger, M. and Ertl, T.},
  title  = {{Hierarchical Splatting of Scattered 4D Data}},
  year   = {2004},
  pages  = {64--72},
  volume = {{24}},
  number = {{4}},
  journal = {{Computer Graphics and Applications}},
  note = {{submitted version}}
}