References
COPD Foundation (2012). About COPD. COPD Foundation. Retrieved August 13, 2012, from www.copdfoundation.org/COPDYou/AboutCOPD.aspx.
Channing Bete Company (2006). Learning to Live with COPD. Channing Bete Company.
American College of Chest Physicians (2004). Living Well with COPD. American College of Chest Physicians.
PERF (2012). The Importance of Proper Breathing Techniques. PERF. Retrieved August 13, 2012, from www.perf2ndwind.org/html/breathing.html.
UPMC (2012). COPD: Chronic Obstructive Pulmonary Disease. UPMC. Retrieved August 13, 2012, from http://www.upmc.com.
