Alam, M., M. Raheen, K. Iqbal, and M. Chowdhury. “Headache Following Spinal Anaesthesia: A Review on Recent Update”. Journal of Bangladesh College of Physicians and Surgeons, vol. 29, no. 1, Mar. 2011, pp. 32-40, doi:10.3329/jbcps.v29i1.7169.