Čović, Filip, et al. “The Quality of Sleep Estimated by the Pittsburgh Sleep Quality Index in Patients With Mild and Severe Obstructive Sleep Apnea”. Annals of Biomedical and Clinical Research, vol. 2, no. 1, July 2023, pp. 8-13, https://abcr-mefmo.org/index.php/abcr/article/view/20.