Jurgen P. Schulze, U. Wossner, SP Walz, and U Lang.
  <b>Volume Rendering in a Virtual Environment</b>.
  <i>Proceedings of 5th IPTW and Eurographics Virtual Environments</i>,
  2001.
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Schulze-2001-VRV.bib">(bibtex:
  Schulze-2001-VRV)</A>.<br />