1. Centers for Disease Control and Prevention. CDC briefing on public health investigation of human cases of Swine influenza. cited 2009 Apr 23. Available from: URL: http://www.cdc.gov/media/transcripts/2009/t090423.htm
2. Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans
3. World Health Organization. Influenza-like illness in the United States and Mexico. cited 2009 Apr 24. Available from:URL: http://www.who.int/csr/don/2009_04_24/en/index.html
4. World Health Organization. World now at the start of 2009 influenza pandemic. cited 2009 Jun 11. Available from: URL: http://www.who.int/mediacentre/news/statements/2009/h1n1_pandemic_phase6_20090611/en/index.html