@InProceedings{vis02-weiskopf,
  author = {Weiskopf, D. and Engel, K. and Ertl, T.},
  title  = {{Volume Clipping via Per-Fragment Operations in Texture-Based Volume Visualization}},
  year   = {2002},
  pages  = {93-100},
  booktitle = {{Proceedings of IEEE Visualization '02}}
}