Santos, José Américo Conde, et al. “Cultivars Height Hoeing Number and Harvest Periods Influence on Weeds Incidence and Corn Grains Yield”. Pesquisa Agropecuaria Brasileira, vol. 22, no. 5, Apr. 2014, pp. 501-3, doi:10.1590/S1678-3921.pab1987.v22.14373.