U.M. Norberg.
  <i><b>Vertebrate flight: mechanics, physiology, morphology,
  ecology and evolution</b></i>.
  Springer-Verlag, Berlin, 1990.
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Norberg-1990-VFM.bib">(bibtex:
  Norberg-1990-VFM)</A>.<br />