David G. Schleicher, Kate L. Barnes, and Nicole F. Baugh.
  <b>Photometry and Imaging Results for Comet 9P/Tempel 1 and Deep
  Impact: Gas Production Rates, Postimpact Light Curves, and Ejecta Plume
  Morphology</b>.
  <i>The Astronomical Journal</i>, 2006.
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Schleicher-2006-PIR.bib">(bibtex:
  Schleicher-2006-PIR)</A>.<br />