Pereira dos Santos, Henrique, et al. “Effect of Winter Crops under No-Tillage on Soybean Grown in Crop Rotation Systems”. Pesquisa Agropecuaria Brasileira, vol. 33, no. 3, Mar. 1998, pp. 289-95, doi:10.1590/S1678-3921.pab1998.v33.4846.