Wenjin Zhou and David H. Laidlaw.
 <b>Measurement of axon radii distribution in orientationally
  unknown tissue using angular double-pulsed gradient spin echo (double-PGSE)
  NMR</b>.
 In <em>ISMRM</em>, 2011.
  <a href="http://vis.cs.brown.edu/docs/pdf/g/Zhou-2011-MAR.pdf.html">(pdf)</a>
  <a href="http://vis.cs.brown.edu/results/bibtex/Zhou-2011-MAR.bib">(bibtex:
  Zhou-2011-MAR)</a>.