David H. Laidlaw, W. Benjamin Trumbore, and John F. Hughes.
  <b>Constructive Solid Geometry for Polyhedral Objects</b>.
  In <i>SIGGRAPH</i>, pages 161-170, August 1986.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/g/Laidlaw-1986-CSG.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Laidlaw-1986-CSG.bib">(bibtex:
  Laidlaw-1986-CSG)</A>.<br />