Qazi, Hammad Ali, Jamil Ahmed Soomro, Tahira Kalisar Soomro, Fahmida Akhtar Soomro, Fahira Rasheed, and Anjum Hashmi. 2009. “Spirometric Screening of Chronic Obstructive Pulmonary Disease in Smokers Presenting to Tertiary Care Centre”. Journal of Medicine 10 (2):40-44. https://doi.org/10.3329/jom.v10i2.2811.