1. Cruise industry overview—marketing edition—2006 [online]. New York: Cruise Lines International Association (US); 2006. [cited 2007 Mar 15]. Available from: www.cruising.org/press/overview%202006/ind_overview.cfm.
2. Discover cruises—annual cruise review 2006 [online]. London: Passenger Shipping Association [online]. May 2006. [cited 2007 Mar 29]. Available from: http://www.discover-cruises.co.uk/content%5Cusefuldocs/acr2005.pdf
3. Boyd L. Brief history of the passenger ship history [online]. Durham (NC): Duke University; 1999. [cited 2006 Jan 30]. Available from: http://scriptorium.lib.duke.edu/adaccess/ship-history.html.
4. Travelers' health: yellow book. Health information for international travelers, 2005–2006. Chapter 7 Conveyance and transportation issues, cruise travel [online]. Atlanta: Centers for Disease Control and Prevention, Department of Health and Human Services (US); [date unknown] [cited 2006 Jan 29] Available from: www2.ncid.cdc.gov/travel/yb/utils/ybGet.asp?section=transportation&obj=cruise.htm&cssNav=browsecyb.
5. Infectious diseases on cruise ships;Minooee;Clin Infect Dis,1999