Resources:

• http://www.cdc.gov/flu/
• http://www.evolution.berkeley.edu/evolibrary/news/051115_birdflu
• http://www.college.ucla.edu/webproject/micro12/m12webnotes/viralevolution.htm
• http://en.wikipedia.org/wiki/Hemagglutinin
• http://en.wikipedia.org/wiki/Virus
• http://en.wikipedia.org/wiki/Flu_virus
• http://en.wikipedia.org/wiki/Influenza
• http://micro.magnet.fsu.edu/cells/viruses/influenzavirus.html