TY  - JOUR 
T1  - Plasma and cerebrospinal fluid alfentanil, butorphanol, and morphine concentrations following caudal epidural administration in horses
JO  - Ciência Rural
A1  - Natalini, Cláudio Corrêa
SN  - 0103-8478
UL  - 10.1590/S0103-84782006000500014
VL  - 36 
Y1  - 2006
PB  - Brasil 
ER  -