A. Hedenstrom, M. Rosen, and G. R. Spedding.
  <b>Vortex wakes generated by robins Erithacus rubecula during
  free flight in a wind tunnel</b>.
  <i>Journal of The Royal Society Interface</i>, 3(7):263-276, April
  2006.
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Hedenstrom-2006-VWG.bib">(bibtex:
  Hedenstrom-2006-VWG)</A>.<br />