Daniel Keefe.
  <b>PhD Defense Talk</b>.
  Brown University, 2007.
  Unpublished
  <A HREF="http://vis.cs.brown.edu/docs/pdf/bib/g/Keefe-2007-DEF.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Keefe-2007-DEF.bib">(bibtex:
  Keefe-2007-DEF)</A>.<br />