Lucas, Dionéia Daiane Pitol, et al. “Water Excess in Different Soils and Sowing Times for Sunflower in the State of Rio Grande Do Sul, Brazil”. Pesquisa Agropecuaria Brasileira, vol. 50, no. 6, June 2015, pp. 431-40, doi:10.1590/S1678-3921.pab2015.v50.20360.