Gertsch, J. H., Basnyat, B., Johnson, E. W., Onopa, J., & Holck, P. S. (2004). 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). BMJ Publishing Group Ltd.

Gertsch, Jeffrey H., Buddha Basnyat, E William Johnson, Janet Onopa, and Peter S. Holck. 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). BMJ Publishing Group Ltd, 2004.

Gertsch, Jeffrey H., et al. 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). BMJ Publishing Group Ltd, 2004.