Ahmed, N.U. et al. 2014. Addition of clonidine or fentanyl with bupivacaine for supraclavicular brachial plexus blocks in upper limb surgery - a randomized comparative study. Journal of the Bangladesh Society of Anaesthesiologists. 24, 1 (Aug. 2014), 3–7. DOI:https://doi.org/10.3329/jbsa.v24i1.19792.