Meitei, A. J.; Rubina, O.; PKS, L.; I., J. S.; Ingudum, D.; R., M. R. Evaluation of Intrathecal Bupivacaine Alone, Bupivacaine With Butorphanol and Bupivacaine With Dexmedetomidine for Lower Segment Caesarean Section: A Randomized Control Trial. Int J Basic Clin Pharmacol 2016, 5, 2675-2682.