da Silva, Paulo Regis Ferreira, and Alexandre Lima Nepomuceno. 1991. “Effect of Plant Arrangement on Grain Yield, Yield Components, Oil Content and Weed Control in Sunflower”. Pesquisa Agropecuaria Brasileira 26 (9):1503-8. https://doi.org/10.1590/S1678-3921.pab1991.v26.3491.