Ahmed, Naseer, Afsheen Maqsood, Tariq Abduljabbar, and Fahim Vohra. “Tobacco Smoking a Potential Risk Factor in Transmission of COVID-19 Infection: COVID-19 Transmission and Tobacco Smoking”. Pakistan Journal of Medical Sciences 36, no. COVID19-S4 (May 19, 2020). Accessed March 28, 2024. https://www.pjms.org.pk/index.php/pjms/article/view/2739.