1. 1. Bradoo R. Anatomic principles of Endoscopic sinus surgery: A step by step approach. New Delhi: Jaypee Brothers; 2005.
2. 2. Sheetal D, Devan PP, Manjunath P, et al. CT PNS - Do we really require before FESS? Journal of Clinical and Diagnostic Research [serial online] 2011 April [cited: 2013 Dec 13 ]; 5:179-181
3. 3. Zojaji R, Mirzadeh MM, Naghibi S. Comparative Evaluation of Preoperative CT Scan and Intraoperative Endoscopic Sinus Surgery Findings in Patients with Chronic Rhinosinusitis. Iran J Radiol 2008; 5(2):77-82.
4. 4. Patel AK, Patel A, Singh B, Sharma M K. The study of functional endoscopic sinus surgery in patients of sinus headache. International journal of Biology and Medical research. 2012;3 (3):1924-1930.
5. 5. Naghibi S, Zojaji R, Hesari MK, Hashemi AH. Sinus CT scan and Functional Endoscopic Sinus Surgery findings in chronic sinusitis: A Comparative Study. Iranian Journal of Radiology.2008; 5(S1): 13-13.