Khan B N, Dr. Dastagir, Dr. Aditya Dharman, Dr. Rona Thomas, Dr. Mohammad Javad Hashemi, and Dr. Setareh Dastyar Haghighi. 2020. “A Systematic Review of Covid-19 Patients With COPD As Comorbidity ”. International Journal of Medical Studies 5 (9), 1-10. http://ijmsonline.in/index.php/ijms/article/view/144.