Evaluation of the Pulmonary Function Test (PFT) in Patients Affected by Severe COVID-19 Pneumonia: 6 to 12 Weeks After Discharge - Soleymani Babadi, Akbar; Kashefizadeh, Alireza; Dalili, Nooshin; Ohadi, Laya; Gheisoori, Abbas; Kazemizadeh, Hossein (Acta Medica Iranica, 2021)