1. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease 2020 report [Internet]. Global Initiative Chronic Obstructive Lung Dis. 2020. https://goldcopd.org/wp-content/uploads/2019/11/GOLD-2020-REPORT-ver1.0wms.pdf
2. Ascertainment of cause-specific mortality in COPD: operations of the TORCH Clinical Endpoint Committee
3. National Center for Immunization and Respiratory Diseases. Pneumococcal vaccination: information for healthcare professionals; [updated 2019 Dec 9]. https://www.cdc.gov/vaccines/vpd/pneumo/hcp/index.html.
4. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2019–20 Influenza Season
5. World Health Organization. Chronic obstructive pulmonary disease (COPD); 2022 [updated 2022 May 20; accessed 2022 June 13]. https://www.who.int/news-room/fact-sheets/detail/chronic-obstructive-pulmonary-disease-copd.