Lawrence R. Frank.
  <b>Characterization of Anisotropy in High Angular Resolution
  Diffusion-Weighted MRI</b>.
  <i>Magnetic Resonance in Medicine</i>, 47:1083-1099, 2002.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/bib/g/Frank-2002-CAH.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Frank-2002-CAH.bib">(bibtex:
  Frank-2002-CAH)</A>.<br />