BALARAJU TC, et al. “COMPARATIVE EVALUATION OF ORAL CLONIDINE AND INTRAVENOUS CLONIDINE PREMEDICATION IN FUNCTIONAL ENDOSCOPIC SINUS SURGERY”. International Journal of Pharma and Bio Sciences, vol. 4, no. 1, Mar. 2013, pp. 587-91, https://ijpbs.net/index.php/journal/article/view/2065.