Venegas, V.H.A. et al. 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 (Apr. 2014), 145–152. DOI:https://doi.org/10.1590/S1678-3921.pab1987.v22.14263.