European Space Agency.
  <b>Global Earth Observation System of Systems, 10 year
  Implementation Plan Reference Document</b>.
  ESA Publications Division, Feb 2005.
  <A HREF="http://vis.cs.brown.edu/results/bibtex/ESA-2005-GEO.bib">(bibtex:
  ESA-2005-GEO)</A>.<br />