Santos, Henrique Pereira dos, et al. “Effect of Crop Rotation on Wheat in No-Tillage System, in Guarapuava, PR”. Pesquisa Agropecuaria Brasileira, vol. 31, no. 4, Apr. 1996, pp. 259-67, doi:10.1590/S1678-3921.pab1996.v31.4479.