Filho, Moacyr Bernardino Dias, et al. “Concentration, Uptake and Use Efficiency of N, P and K in <i>Panicum maximum< i> Jacq. Cv. Tobiatã under Water Stress”. Pesquisa Agropecuaria Brasileira, vol. 27, no. 3, Mar. 1992, pp. 381-7, doi:10.1590/S1678-3921.pab1992.v27.3659.