J.M.V. Rayner, P.W. Viscardi, S. Ward, and J.R. Speakman.
  <b>Aerodynamics and energetics of intermittent flight in birds</b>.
  <i>American Zoologist</i>, 41:188-204, 2001.
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Rayner-2001-AEI.bib">(bibtex:
  Rayner-2001-AEI)</A>.<br />