1. Centers for Disease Control and Prevention (CDC). FastStats. Retrieved August 3, 2017, from http://www.cdc.gov/nchs/fastats/asthma.htm .
2. American Lung Association (ALA). Trends in COPD (Chronic Bronchitis and Emphysema): Morbidity and mortality. Retrieved August 3, 2017, from http://www.lung.org/assets/documents/research/copd-trend-report.pdf .
3. Centers for Disease Control and Prevention (CDC). Vital signs: Asthma prevalence, disease characteristics, and self-management education—United States, 2001–2009. MMWR. Retrieved August 3, 2017, from http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6017a4.htm?s_cid=mm6017a4_w .
4. American Academy of Allergy Asthma and Immunology. Asthma statistics. Retrieved August 3, 2017, from http://www.aaaai.org/about-the-aaaai/newsroom/asthma-statistics.aspx .
5. National Heart, Lung, and Blood Institute. Disease statistics. Retrieved August 3, 2017, from http://www.nhlbi.nih.gov/about/documents/factbook/2012/chapter4 .