Damian, Júnior Melo, et al. “N, P or K Doses on the Dry Matter and Crude Protein Yield in Maize and Sorghum for Silage”. Pesquisa Agropecuária Tropical [Agricultural Research in the Tropics], vol. 47, no. 1, Mar. 2017, pp. 53-61, https://doi.org/10.5216/pat.v47i1.42722.