Nakamura, G., Ganem, E.M., Módolo, N.S.P., Rugolo, L.M.S. de S. and Castiglia, Y.M.M. 2008. Labor analgesia with ropivacaine added to clonidine: a randomized clinical trial. São Paulo Medical Journal. 126, 2 (Mar. 2008), 102–106.