Dr. Oza Harsh Nikhilkumar, and Dr. Jyoti Vora. 2018. “Identifying Risk Factors for Acute Exacerbations of Chronic Obstructive Pulmonary Disease”. Global Journal of Medical Research 18 (F5):1-6. https://medicalresearchjournal.org/index.php/GJMR/article/view/1597.