Chacur, M. G. M.; Dias, H. S.; Papa, P. de M.; Papa, F. O.; Melo-Onã, C. M. Effect of Refrigeration Systems Upon Frozen Bull Sperm Viability Assessed by Computer-Assisted Sperm Analysis and Fluorescent Probes. Sem. Ci. Agr. 2012, 33, 1923-1930.