Husain, Aamir, Salman Shakoor, and Istikhar Ali Sajjad. “FEV1/FEV6/As/an/Alternative/to/FEV1/FVC/in/the/Spirometric/Detection/of/Airway/Obstruction/in/Chronic/Smokers”. Annals of Punjab Medical College 10, no. 3 (August 28, 2016): 147–151. Accessed March 9, 2026. https://apmcfmu.com/index.php/apmc/article/view/281.