Baio, F. H. R., D. C. Neves, C. N. da S. Campos, and P. E. Teodoro. “Relationship Between Cotton Productivity and Variability of NDVI Obtained by Landsat Images”. Bioscience Journal, vol. 34, no. 6, Dec. 2018, pp. 197-05, doi:10.14393/BJ-v34n6a2018-39583.