Santos, Henrique Pereira dos, et al. “Effects of Winter Crops and Rotation Systems on Some Agronomic Characteristics of Soybean”. Pesquisa Agropecuaria Brasileira, vol. 32, no. 11, Nov. 1997, pp. 1141-6, https://doi.org/10.1590/S1678-3921.pab1997.v32.4767.