M. O. Ward.
  <b>Creating and Manipulating N-Dimensional Brushes</b>.
  In <i>Proceedings of Joint Statistical Meeting</i>, pages 6-14,
  August 1997.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/bib/g/Ward-1997-CMN.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Ward-1997-CMN.bib">(bibtex:
  Ward-1997-CMN)</A>.<br />