Lin, H.-C., Heath, A. M., Pugh, D. G. and Trachte, E. A. (2003) “Comparison of the Analgesic Effect of Clonidine and Lidocaine When Administered Epidurally in Cattle”, The Bovine Practitioner, 37(1), pp. 83–88. doi: 10.21423/bovine-vol37no1p83-88.