1. World Health Organization. Influenza (seasonal). Fact Sheet No. 211. Geneva: WHO, Last updated April 2009. Available at: http://www.who.int/mediacentre/factsheets/fs211/en/index.html. (Accessed 2010 Jul 31)
2. Influenza in Travelers: Epidemiology, Risk, Prevention, and Control Issues
3. Influenza Virus Infection in Travelers to Tropical and Subtropical Countries
4. World Health Organization. Vaccine‐preventable disease and vaccines. In: International travel and health. Ch. 6. Geneva: WHO, 2010. Available at: http://www.who.int/ith/ITH2010chapter6.pdf. (Accessed 2010 Jul 31)
5. Nitsch‐Osuch A. Influenza as a health problem of sea travelers. Int Marit Health 2008; 59(1–4):103–112.