Campos, Caio Ferraz de, et al. “Periods of Weed Interference in Maize Crops Cultivated in the First and Second Cycles”. Semina: Ciências Agrárias, vol. 37, no. 5, Oct. 2016, pp. 2867-80, doi:10.5433/1679-0359.2016v37n5p2867.