Z. Mashaba, G. Chirima, J. O. Botai, L. Combrinck, C. Munghemezulu, and E. Dube, “Forecasting winter wheat yields using MODIS NDVI data for the Central Free State region”, S. Afr. J. Sci., vol. 113, no. 11/12, Nov. 2017, doi: 10.17159/sajs.2017/20160201.