1. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for diagnosis, management, and prevention of chronic obstructive pulmonary disease. (Updated 2015). http://www.goldcopd.org.
2. Holland AE, Hill CJ, Jones AY, McDonald CF. Breathing exercises for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2012; 17:CD008250.
3. Redllch CA, Tarlo SM, Hankinson JL, Townsend MC, Eschenbacher WL, von Essan SG, et al. Official American Thoracic Society Technical Standards:spirometry in the occupational setting. Am J Respir Crit Care Med 2011;189:984–994.
4. Tydeman DE, Chandler AR, Graveling BM, Culot A, Harrison BD. An investigation into the effects of exercise tolerance training on patients with chronic airways obstruction. Physiotherapy 1984;70:261–264.
5. Ward JA, Akers G, Ward DG, Pinnuck M, Williams S, Trott J, et al. Feasibility and effectiveness of a pulmonary rehabilitation program in a community hospital setting. Br J Gen Pract 2002;52:539–542.