Alqahtani, J. S., Oyelade, T., Aldhahir, A. M., Alghamdi, S. M., Almehmadi, M., Alqahtani, A. S., . . . Hurst, J. R. (2020). Prevalence, Severity and Mortality associated with COPD and Smoking in patients with COVID-19: A Rapid Systematic Review and Meta-Analysis. Plos One, 15(5). doi:10.1371/journal.pone.0233147 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233147