Suleman, Amir, Raza Ullah, Hamid Nisar, Shahida Naz, and Rab Nawaz Khan. “Prevalence of Influenza Vaccination in Chronic Obstructive Pulmonary Disease Patients”. Pakistan Journal of Chest Medicine 24, no. 2 (August 29, 2018): 86–90. Accessed April 17, 2026. https://pjcm.net/index.php/pjcm/article/view/519.