Malikka, A., J. Kandoth, and S. George. “A Study on the Cavity Problems in Patients Who Have Undergone Functional Endoscopic Sinus Surgery”. International Journal of Health and Clinical Research, vol. 3, no. 4, Aug. 2020, pp. 153-62, https://ijhcr.com/index.php/ijhcr/article/view/173.