Khalid, Awais, et al. “Comparison Between Sphenopalatine Ganglion Block And Greater Occipital Nerve Block in the Management of Post-Dural Puncture Headache in Patients Refractory to Oral Therapy”. Pakistan Armed Forces Medical Journal, vol. 76, no. 5, Sept. 2026, pp. 675-9, https://doi.org/10.51253/pafmj.v76i5.13253.