Guimarães, Clóvis Ribeiro, et al. “Reduction of Crude Protein in Diets Fed to Lactating Holstein-Gyr Cows”. Pesquisa Agropecuaria Brasileira, vol. 53, no. 7, Oct. 2018, pp. 858-65, https://doi.org/10.1590/S1678-3921.pab2018.v53.25398.