Qaseem A, Wilt TJ, Weinberger SE, Hanania NA, Criner G, van der Molen T, Marciniuk DD, Denberg T, Schünemann H, Wedzicha W, MacDonald R, and Shekelle P for the American College of Physicians, the American College of Chest Physicians, the American Thoracic Society, and the European Respiratory Society. Diagnosis and Management of Stable Chronic Obstructive Pulmonary Disease: A Clinical Practice Guideline Update from the American College of Physicians, American College of Chest Physicians, American Thoracic Society, and European Respiratory Society. Ann Intern Med [Internet]. 2011 Aug 2 [cited 2013 Jan 22];155(3);171–191. Available from: http://www.thoracic.org/statements/resources/respiratory-disease-adults/copd-guideline-acp-ats-ers-accp%20-abstract.pdf