T. Karaaslan, E. Karaaslan, O. Uysal, and M. Gunduz, “Evaluation of Respiratory Functions with Spirometry in Patients with SARS-CoV-2 Pneumonia: Pulmonary Function Tests in SARS-CoV-2 Pneumonia”, Med Sci Discov, vol. 8, no. 9, pp. 538–545, Sep. 2021.