Sobreira, Fabrício Moreira, et al. “Nitrogen and Potassium Fertigation in Coffee at the Formation Phase, With High Plant Density”. Pesquisa Agropecuaria Brasileira, vol. 46, no. 1, Mar. 2011, pp. 9-16, doi:10.1590/S1678-3921.pab2011.v46.9305.