Santos, R.R. dos (2006) “Toxicity test and cryopreservation of sheep isolated preantral follicles using glycerol, ethylen glycol, dimethil sulfoxyde and propanediol”, Brazilian Journal of Veterinary Research and Animal Science, 43(2), pp. 250–255. doi:10.11606/issn.1678-4456.bjvras.2006.26506.