Effect of cysteine and cysteamine supplementation on nuclear maturation of bitch oocytes obtained during the preovulatory stage - Pires-Buttler, E. A. [UNESP]; Ribeiro, A. P. C. [UNESP]; Apparicio, M. [UNESP]; Vicente, W. R. R. [UNESP] (Blackwell Publishing, 2008)