Eissa R.E, Abo-Elnassr L.M; Amin S.M.and Mohamed R.M. "The Effect of Adding Dexmedetomidine or Fentanyl to Levobupivacaine for Ultrasound-guided Supraclavicular brachial plexus block in Upper Extremity Sugeries", The Egyptian Journal of Hospital Medicine, 73, 2, 2018, 6004-6009. doi: 10.21608/ejhm.2018.12372