Ahmed, A., M. Fawzy, M. A. R. Nasr, A. HussamHussam, E. fouad, H. Aboueldahab, D. Saad, S. Osman, R. S. Fahmy, M. Farid, et al.,  "Ultrasound-guided quadratus lumborum block for postoperative pain control in patients undergoing unilateral inguinal hernia repair, a comparative study between two approaches",  BMC, vol. 19, issue 1, pp. 184, 2019.