Banerjee, A., Bhattacharya, P., Wankhede, R.G., Rudra, A., Sengupta, S. and Sen, S. 2020. Study the impact of ketamine, clonidine and combination of ketamine-clonidine on cardiovascular system during pre and postoperatively: A double blind, placebo controlled study. International Journal of Health and Clinical Research. 3, 4 (Aug. 2020), 109–118.