Peter S. Stevens.
  <i><b>Patterns in Nature</b></i>.
  Little Brown and Co, 1974.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/bib/g/Stevens-1974-PNA.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Stevens-1974-PNA.bib">(bibtex:
  Stevens-1974-PNA)</A>.<br />