1. Planning influenza vaccination programs: a cost benefit model;IG Duncan;Cost Eff Resour Alloc,2012
2. World Health Organization. Influenza (seasonal) 2016 [cited 2017 April 25]. http://www.who.int/mediacentre/factsheets/fs211/en/.
3. The evolving history of influenza viruses and influenza vaccines;C Hannoun;Expert Rev Vaccines,2013
4. Expansion of seasonal influenza vaccination in the Americas;AM Ropero-Alvarez;BMC Public Health,2009
5. Seasonal influenza vaccine use in low and middle income countries in tropics and subtropics: a systematic review;S Hirve,2015