Venegas, Victor Hugo Alvarez, Francisco M. Freire, and Paulo Tácito G. Guimarães. 2014. “Optimum Relative Concentrations of Nitrogen, Phosphorus and Sulfur in Coffee Fertilization in a Dark-Red Latosol, at Machado, MG, Brazil”. Pesquisa Agropecuaria Brasileira 22 (2):145-52. https://doi.org/10.1590/S1678-3921.pab1987.v22.14263.