dos Santos, Elson Soares, et al. “Genetic Progress of the Milking Gyr Herd of Umbuzeiro, PB, Brazil”. Pesquisa Agropecuaria Brasileira, vol. 25, no. 9, Apr. 2014, pp. 1339-48, doi:10.1590/S1678-3921.pab1990.v25.19479.