Yu-Chien Wu, Aaron S. Field, Moo K. Chung, Benham Badie, and Andrew L.
  Alexander.
  <b>Quantitative Analysis of Diffusion Tensor Orientation:
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  <i>Magnetic Resonance in Medicine</i>, 52:1146-1155, 2004.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/bib/g/Wu-2004-QAD.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Wu-2004-QAD.bib">(bibtex:
  Wu-2004-QAD)</A>.<br />