P. R. Ferreira da Silva, W. Wendt, and A. Brondani da Rocha, “Effect of soil management system and fertilization level on sunflower cultivated after Avena strigosa”, PAB, vol. 32, no. 6, pp. 641–647, Jun. 1997, doi: 10.1590/S1678-3921.pab1997.v32.4694.