1. Influenza (Seasonal) World Health Organization, April 2009. Available from: http://www.who.int/mediacentre/factsheets/fs211/en/. [Last accessed on 2012 Apr 16].
2. Epidemiology and control of influenza;Rao;Natl Med J India,2003
3. World Health Organization. Pandemic (H1N1) 2009-Update 112, 6 August 2010. Available from: http://www.who.int.csr/don/2010_08_06/en/index.hmt [Last accessed on 2011 Oct 12].
4. World Health Organization. Global alert and response (GAR) (2011). Summary review of the 2010-2011 northern hemisphere winter influenza season. Available from: http://www.who.int/influenza/surveillance_monitoring/2010_2011_GIP_surveillance_seasonal_review/en/. [Last accessed on 2012 Aug 28].
5. Ministry of Health and Family Welfare, Government of India. Pandemic Influenza A (H1N1) situational update 16 May 2009. Available from: http://mohfw-h1n1.nic.in/documents/PDF/SituationalUpdatesArchives/may/Situational%20Updates%20on%2016.05.2009.pdf. [Last accessed on 2011 Oct 12].