Hussien, A. E., Abdel Halim, M. A. G. (2019). 'A comparative study between the effect of intrathecal hyperbaric bupivacaine with fentanyl and hyperbaric levobupivacaine with fentanyl for knee arthroscopy', The Scientific Journal of Al-Azhar Medical Faculty, Girls, 3(1), pp. 44-49. doi: 10.4103/sjamf.sjamf_47_18