Andreas Wenger, Daniel Keefe, Song Zhang, and David H. Laidlaw.
  <b>Interactive Volume Rendering of Thin Thread Structures within
  Multivalued Scientific Datasets</b>.
  <i>IEEE Transactions on Visualization and Computer Graphics</i>,
  10(6):664-672, November/December 2004.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/g/Wenger-2004-IVR.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Wenger-2004-IVR.bib">(bibtex:
  Wenger-2004-IVR)</A>.<br />