Omer, T., A. Anwar, H. N. Ahmed, M. H. Khan, M. Barlas, and A. Zia. “Comparison of Post-Dural Puncture Headache Incidence Among Patients Undergoing Spinal Anaesthesia for Elective Caesarean Section by Using Quincke 25-G and 29-G Spinal Needles”. International Journal of Research in Medical Sciences, vol. 9, no. 9, Aug. 2021, pp. 2588-92, doi:10.18203/2320-6012.ijrms20213397.