Fonseca, Eliana Lima da, et al. “Spectral Characterization of Paspalum Notatum under Different Nitrogen Fertilization”. Pesquisa Agropecuaria Brasileira, vol. 37, no. 3, Mar. 2002, pp. 365-71, https://doi.org/10.1590/S1678-3921.pab2002.v37.6349.