Sousa, C.F. de, Grangeiro, L.C., Sousa, V. de F.L., Carneiro, J.V. e Rodrigues, G.S.O. 2020. Efficiency of nitrogen usage in maize cultivars for grain production. Científica. 48, 2 (jun. 2020), 128–132. DOI:https://doi.org/10.15361/1984-5529.2020v48n2p128-132.