Epiphanio, José C. N., et al. “Vegetation Indices for Remote Sensing of Beans (<i>Phaseolus vulgaris< I> L.)”. Pesquisa Agropecuaria Brasileira, vol. 31, no. 6, June 1996, pp. 445-54, doi:10.1590/S1678-3921.pab1996.v31.4503.