Saha Somnath, Coffman Darren D, Smits Ariel K
Section of General Internal Medicine, Portland VA Medical Center, and the Division of General Internal Medicine and Geriatrics, Oregon Health and Science University, Portland, USA.
N Engl J Med. 2010 Feb 18;362(7):e18. doi: 10.1056/NEJMp0912938. Epub 2010 Feb 3.