Karim, M., D. Banik, Q. Huda, A. Hye, D. Banik, and F. Begum. “Effect of Site of Injection on Spread of Spinal Anaesthesia With Hyperbaric Bupivacaine”. Bangladesh Journal of Obstetrics &Amp; Gynaecology, vol. 23, no. 1, Aug. 2009, pp. 15-19, doi:10.3329/bjog.v23i1.3052.