Khan, Z. ullah and Malik, K.Z. (2006) “CHRONIC MAXILLARY SINUSITIS, AN UNCOMMON AETIOLOGICAL FACTOR OF HEADACHE”, Pakistan Armed Forces Medical Journal, 56(2), pp. 138–142. Available at: https://www.pafmj.org/PAFMJ/article/view/1507 (Accessed: 30 August 2025).