GertschJ.H.BasnyatB.JohnsonE.W.OnopaJ.HolckP.S.Randomised, double blind, placebo controlled comparison of ginkgo biloba and acetazolamide for prevention of acute mountain sickness among Himalayan trekkers: The prevention of high altitude illness trial (PHAIT). British Medical Journal (2004) 328: p. 797 Accessed via www.bmj.com/cgi/content/abstract/328/7443/797 [date last accessed 21.04.2009].