1. Tourism highlights 2011 edition. World Tourism Organization. Available at: http://mkt.unwto.org/sites/all/files/docpdf/unwtohighlights11enhr_0.pdf. Accessed September 14, 2011.
2. National statistics. Travel trends 2010. A report on the International Passenger Survey. Available at: http://www.ons.gov.uk/ons/search/index.html?newquery=travel+trends; http://www.statistics.gov.uk/downloads/theme_transport/traveltrends2004.pdf. Accessed June 20, 2012.
3. Spectrum of disease and relation to place of exposure among ill returned travelers;Freedman;N Engl J Med,2006
4. Variability in malaria prophylaxis prescribing across Europe: a Delphi method analysis;Calleri;J Travel Med,2008
5. The incidence of malaria in travellers to South-East Asia: is local malaria transmission a useful risk indicator?;Behrens;Malar J,2010